# Accuracy Tracking



## Sabresoft

As a little exercise I have been tracking the accuracy of several of my watches, 4 TC, a precisionist and a standard quartz that looked to be keeping fairly good time. I have not been concerned about temperature as a variable and realize that this could impact my results significantly. What I was more looking for was to see how well the various watches were keeping accuracy over time, as they are part of a larger collection that gets worn on the basis of a watch change every 1 - 3 days depending on mood and needs. As I also have several AT watches that are part of the wrist rotation it means that any given watch could conceivably not see wrist time for a couple of weeks (or longer for lesser favourites).

The watches in the test were: 
- Breitling Airwolf Raven
- Bulova Precisionist Claremont
- Maurice Lacroix Miros Diver
- Seiko Worldtime Flightmaster SNJ017
- Sinn UX

I also am testing the Christopher Ward C70 Brooklands COSC, but currently have too few data points to use for the chart.

My methodology was to check the watches by the stopwatch method using my Citizen Skyhawk AT (after making sure that it had made a successful sync within the last day). At the start of the test I set all the watches and then took an initial reading to account for the small setting inaccuracy (the worst was off by ⅓ of a second based on my pathetic reaction times). At each test point I took 5 readings (sometimes more if one reading was significantly different from the others, replacing that reading). The readings were based on a 15 second comparison period, starting the reading as the second hand passed a certain marker on the "checked" watch, and taking the stopwatch reading on the AT watch as it's second hand hit the same marker plus 15 seconds. I took the average and then computed an expected SPY value based on the following formula:

SPY (est) = (Reading - 15 - original offset ) * 365 / (test date - start date)

I tabulated the values for each of the 5 watches, and while seeing relatively as expected performance from most of the watches I was noticing that for some there seemed to be an increase in the projected SPY as time progressed. It was at this point that I decided to create a plot of the SPY versus days (test date minus start date), and then use Excel's trend line tool to project out to 365 days. This captures an "acceleration" effect. The chart below shows the results:









The Breitling and Sinn show relatively flat curves (lines) projecting to -2.76 spy (versus an average estimate right now of -7 spy) for the Breitling and 16.76 spy (versus an average estimate right now of 12.5 spy) for the Sinn. Both fall within COSC (at 25.5 spy), and the current average values are quite acceptable to me. The Sinn will get corrected at the fall and spring time changes, but the Airwolf will go the full 365 days on the test, as time change can be achieved without touching the minutes/seconds.

The Seiko is not providing any real surprise, and even projected out to 365 days is showing about 82 spy, which is better than the monthly range of +/- 15 spm would project to at an annual rate (180 spy).

The Precisionist is not looking anywhere near as good as the advertised claims, but then too is getting very little wrist time. I am sure that its numbers would be better if worn daily, but based on comments I have heard from a number of sources the 10 spy number is suspect.

The real shocker is the Maurice Lacroix Miros Diver (ETA 251.232). While early numbers were projecting a quite low spy, the last three checks were giving 13, 15 and 18 spy. This projects out to a very un COSC, un TC, 64 spy at 365 days! I will continue to monitor this situation, and will contact ML.

I am 121 days into my test and will continue monitoring until 365 days have passed (the Sinn and Precisionist will end the test at the fall time change as their seconds/minutes hands are affected when changing the time). The other 3 can adjust the hour hand independently.


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## Hans Moleman

Great work!
Thanks for doing the donkey work. I hope you can finish an entire year.

I was at first puzzled by what you call the "acceleration" effect. The rate increasing over time.
Even with small periods to measure over and extrapolating to a year, the rate should remain constant?

My guess it is that summer is having an effect here. 
Your measurements will tell.

If you finish a year we can nicely see how each of the watches are affected by the temperature changes over the year.


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## Sabresoft

Hans Moleman said:


> I was at first puzzled by what you call the "acceleration" effect. The rate increasing over time.
> 
> Even with small periods to measure over and extrapolating to a year, the rate should remain constant?


 I would have thought so too. The early data (under 35 days) was a bit erratic, but then a small error in reading say 0.1 sec after say the first 3 days would translate to 10 spy. The same error at 121 days is more like 0.3 spy. The chart and trendline exclude the early data.

There seems to be a definite growth trend in some of the watch data (the ML for example).


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## Hans Moleman

Sabresoft said:


> I would have thought so too. The early data (under 35 days) was a bit erratic, but then a small error in reading say 0.1 sec after say the first 3 days would translate to 10 spy. The same error at 121 days is more like 0.3 spy. The chart and trendline exclude the early data.
> 
> There seems to be a definite growth trend in some of the watch data (the ML for example).


My guess is that the trend will drop once it gets colder. 
All the watches are having to deal with the same temperatures. Some cope better than others, your graph shows that very well.

Looks like the ML copes very badly though, for a TC watch anyway. If the theory holds, that the rise is caused by the weather, then it will drop just as fast.


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## South Pender

If I'm understanding this correctly, you have run the test for 121 days, but have drawn graphs out to 365 days. If we look between 0 and 121 on the graph, we don't see much "acceleration" except for the Miros and Seiko. The Breitling, Sinn, and Precisionist are fairly flat over the time period that has actually taken place. There is absolutely no reason to expect a rising curve when the data points are _spy_ values. Since the watches are in storage for most of the time, unless you are experiencing substantial inside temperature fluctuations (which seems unlikely), I can see no reason whatsoever for the curves to be anything but flat. You are, after all, measuring the same phenomenon simply at different times. This is quite different from measuring rate over time (without the adjustment to _spy_), and it is quite different from graphing _spy_ with a changing temperature abscissa, running, from, for example, 50 F to 90F. This all leads me to think that the construction of a trend line beyond the current state of timing is portraying something that will not actually occur. By far the most revealing part of your graph is at the point 121 on the abscissa. These estimates are quite solid being based on about 4 months of elapsed time.

One or two suggestions for the continuation of this project: (a) use 10 timings (at least) for your average offsets and (b) use a more precise clock as your reference--the NIST clock being one possibility. I've noticed that the signal lag varies with my RC watches.

By the way, none of the above is meant as criticism. Your results are very interesting and valuable and will be even more so after a year's timing.


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## Sabresoft

I realize that there is significant danger in extrapolating future data based on current data, especially when the projection period is longer than the historical data period. At the same time while the Breitling, Sinn and Precisionist lines are flat, the other two do show a pronounced growth over time. The last three readings for the ML were at an annual rate of 13, 15 and 18 spy respectively.

I will continue to monitor these watches, and as time goes on my measured data will increase and my trend line will be shorter, and based on a larger set of data. 

As to the accuracy of the Skyhawk AT, I check it against a NIST source on a few occasions and usually find that it is within 0.25 sec, so I doubt that I am picking up much error in the more recent readings. At 121 days the effect at 365 days would be no more than 0.75 spy. Also if the Skyhawk was causing so much distortion to the results, the Sinn, Breitling and Precisionist data would also be showing disturbing trends. 

I'm not drawing any conclusions yet, but I do find the rapid rise in the ML readings a little disturbing. I doubt that reading accuracy is an issue because I did two separate sets of readings the day that I got the 15 spy value and basically got the same result.


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## Sabresoft

Hans Moleman said:


> My guess is that the trend will drop once it gets colder.
> All the watches are having to deal with the same temperatures. Some cope better than others, your graph shows that very well.


In the winter we would allow the bedroom to drop to about 16C during the day while we were at work, and overnight (we sleep better in a cooler room). In the morning and when we go to bed we set the temp to about 21 C.

We have had a dismal summer, and I'd say that our temperature range has been running in the 20 - 24 C range.

So I can see that there might be some temperature effects impacting the curves. But TC should be less affected, and yet the ML is behaving very strangely.


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## Sabresoft

OK, I decided to take another look at my data. Instead of plotting the SPY estimates for each reading I instead plotted the actual seconds off atomic time at each period, and then fitted a trendline out to 365 days.









The trendline was computed from the last 4 readings. As can be seen, the ML Miros line definitely takes a bend upwards about 4 readings back. The dashed line marked "ML" is where I would have expected the Miros' trendline to actually go.

The table below shows the projected SPY values based on my original method (upper line) and my revised method. The Seiko is looking better at under a minute a year, the Breitling and Sinn are showing 365 day values that are consistent with my average weekly reading based estimates of SPY (7 and 12.5 respectively). The Precisionist is still showing worse than spec at about 29 SPY. And the ML Miros is definitely showing off spec for a TC caliber at around 35 SPY, whereas had it maintained its original trend it would come in at about 11.2 SPY.


SeikoBreitlingSinnMirosPrecisionist81.79-2.7616.7663.9338.3847.77-6.4913.6935.1729.16

I'll follow both methods and see where it takes me. I'd expect both sets of curves to merge (or come close) at the end of the test.


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## Catalin

Sabresoft said:


> OK, I decided to take another look at my data. Instead of plotting the SPY estimates for each reading I instead plotted the actual seconds off atomic time at each period, and then fitted a trendline out to 365 days.
> 
> ...
> 
> The trendline was computed from the last 4 readings. As can be seen, the ML Miros line definitely takes a bend upwards about 4 readings back. The dashed line marked "ML" is where I would have expected the Miros' trendline to actually go.
> 
> The table below shows the projected SPY values based on my original method (upper line) and my revised method. The Seiko is looking better at under a minute a year, the Breitling and Sinn are showing 365 day values that are consistent with my average weekly reading based estimates of SPY (7 and 12.5 respectively). The Precisionist is still showing worse than spec at about 29 SPY. And the ML Miros is definitely showing off spec for a TC caliber at around 35 SPY, whereas had it maintained its original trend it would come in at about 11.2 SPY.
> 
> 
> Seiko
> BreitlingSinnMirosPrecisionist81.79-2.7616.7663.9338.3847.77-6.4913.6935.1729.16
> 
> I'll follow both methods and see where it takes me. I'd expect both sets of curves to merge (or come close) at the end of the test.


Very good work - some of the 'strangeness' in the result might come from not having a very clear measurement on how big the thermal effects are - but in the long-term the average should still be very interesting!


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## h2oflyer

Thanks for doing all the work. After tracking my SBCM023, I started on all of my current quartz watches, but gave up as too much work.

I also used my Skyhawk AT as the time standard and the offset (average -.15) was constant with NIST. I found it was easier and probably more accurate when comparing indexing second hands
side by side while using the stop watch method.

Walter


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## South Pender

Increasing deviation over time from zero offset may be a sign of factors that we haven't yet fully understood. With my two tweaked 9F commemorative GS quartz models, I've seen a little of this and have been unable to explain it. The deviations have grown about 2 _spy_ over period of 7-8 months (e.g., 2 _spy_ in the first 3 months of testing, as opposed to 4 _spy_ in the last 3 months of testing which have begun about 6 months after the end of the first set of readings). I've written it off to random error at this point. Crystal aging seems like another reasonable explanation, and Catalin can comment further on this. If our theories about the latter are correct, we might see a plateauing after a number of months in the graph of _spy_ × elapsed time.


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## artec

Doesn't a jump from 2 spy to 4 spy in only a few months seem awfully fast for crystal aging? I thought Seiko and Citizen both used only pre-aged crystals in their high end movements? 
Anyway, I hope your two commemorative 9Fs learn to behave and level off in their behavior. Neither of my GS are tweaked (one is a 9F and the other 8J) and I haven't had either for long enough to know whether it is accelerating...... time will show.


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## South Pender

artec said:


> Doesn't a jump from 2 spy to 4 spy in only a few months seem awfully fast for crystal aging? I thought Seiko and Citizen both used only pre-aged crystals in their high end movements?
> Anyway, I hope your two commemorative 9Fs learn to behave and level off in their behavior. Neither of my GS are tweaked (one is a 9F and the other 8J) and I haven't had either for long enough to know whether it is accelerating...... time will show.


I haven't seen this small increase as amounting to very much. There has undoubtedly been some small (indoor) temperature fluctuations as well. In addition, both watches have been off-wrist for that time so that the 12 hours per day conditions have not been met.


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## Sabresoft

Ten days later:









I have added the latest readings (today) so we are now at 131 days into the test. I have also added the COSC +/- 25.55 SPY boundaries (based on 0.07 seconds per day).

The Sinn, Breitling, and newly added CW C70 (only 40 days of data) are projecting well within COSC. The Precisionist is slightly outside COSC, not bad, but definitely not the +/- 10 SPY claimed.

The standard quartz Seiko isn't doing too poorly (well within the +/- 120 to 180 SPY of standard quartz). Although I haven't been accurately monitoring my older (non-AT) Citizen Skyhawk, I'd estimate that it is projecting to approximately 23.62 SPY (an earlier test had it at around 33 SPY, neither result too shabby for a non-TC movement).

The Maurice Lacroix Miros Diver is certainly not behaving like a COSC chronometer. I have contacted ML and will have to send the watch back to Switzerland. I'll be curious to see if the CW develops a similar behaviour as it uses the same ETA caliber.

The table below shows the SPY projections for the last two sets of readings:









Maybe when the fall time change comes which will take the Sinn and Precisionist out of the current test I'll start a new test with the Sinn, Precisionist and non-AT Skyhawk.

Time will tell................


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## Eeeb

You could adjust the Miros yourself. It does have that feature.


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## Hans Moleman

At least the 'acceleration' has stopped.
That would be a worry if that continued.


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## South Pender

Nice work, Sabresoft. This kind of long-term accuracy testing is just what's needed. :-!


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## McAllan

Very interesting. Good work!

But I guess there's a factor overlooked. The voltage level. Most clocks and watches speeds up with decreasing voltage level unless they contain compensation for that too.
While I do not have logged it seems quite consistent with my normal clocks and watches I set regularly. Whether it's the dollar store clock in my bathroom (don't want to ruin an expensive one here) that is normally slow but in the few last months of a battery it is eerily dead on. Or my Seiko bedside alarm clock with is normally a fast but the last few months it is very fast.

Although silver cells have a flatter discharge curve than alkaline they're still not as water level flat as the old mercury cells. So to tell anything about aging you either need a constant voltage source or compare several battery discharge cycles with each other. And then you even can't be sure all the batteries are behaving exactly the same - achieving same voltage level at same discharge state etc. even though they may be same designation from same brand - a lot of factors have influence of a battery's performance.


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## Sabresoft

Battery discharge level could be a factor, but all the watches are relatively new, although how long the watch sat "in-stock" before I bought it is anybody's guess. As it is adjustable per an earlier response I am going to continue to monitor it for a while longer, but that low battery theory may just be the answer, and if not, then a little adjustment may just be in order here.


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## South Pender

McAllan said:


> But I guess there's a factor overlooked. The voltage level.


This is not a factor that, in my recollection, has been discussed much in connection with TC watch accuracy. My only recollections about it have had to do with whether or not light-replenished rechargeable batteries might produce less-than-optimal performance in TC modules (as in the "eco-drive" TC Citizen movements). In such cases, so went the theory, fluctuating levels of battery charge might cause decrements in performance. The consensus was, again if I'm remembering correctly, that this shouldn't be a factor affecting accuracy, and I don't believe any empirical evidence was presented suggesting such degrading of accuracy.

I'd really like to see some well-developed theory or, far better, solid, replicated empirical evidence of varying-voltage effects before considering this factor worthy of consideration.


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## Eeeb

South Pender said:


> This is not a factor that, in my recollection, has been discussed much in connection with TC watch accuracy. My only recollections about it have had to do with whether or not light-replenished rechargeable batteries might produce less-than-optimal performance in TC modules (as in the "eco-drive" TC Citizen movements). In such cases, so went the theory, fluctuating levels of battery charge might cause decrements in performance. The consensus was, again if I'm remembering correctly, that this shouldn't be a factor affecting accuracy, and I don't believe any empirical evidence was presented suggesting such degrading of accuracy.
> 
> I'd really like to see some well-developed theory or, far better, solid, replicated empirical evidence of varying-voltage effects before considering this factor worthy of consideration.


Yes, I can't see how applying a higher (or lower) voltage to the crystal would cause it to change resonant frequency... But high (or low) voltage to the electronics can cause unpredictable results and that never increases accuracy.


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## McAllan

Eeeb said:


> Yes, I can't see how applying a higher (or lower) voltage to the crystal would cause it to change resonant frequency... But high (or low) voltage to the electronics can cause unpredictable results and that never increases accuracy.


Basically it's almost like a balance. As the amplitude goes down with voltage level (not necessarily a linear interaction) the longer in it's cycle it's influenced by the driving circuitry as it has to vibrate % wise more to generate enough feedback to the driving circuitry. And in order to keep swinging it needs to be accelerated by the driving circuitry at certain points in the cycle.
Altering load capacitors don't change the crystal's resonance frequency either yet no one here argues that's a way of adjusting the rate.

The best I could find about the subject in a few minutes are this:
http://www.leapsecond.com/pdf/an200-2.pdf
http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA508100


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## Eeeb

McAllan said:


> Basically it's almost like a balance. As the amplitude goes down with voltage level (not necessarily a linear interaction) the longer in it's cycle it's influenced by the driving circuitry as it has to vibrate % wise more to generate enough feedback to the driving circuitry. And in order to keep swinging it needs to be accelerated by the driving circuitry at certain points in the cycle.
> Altering load capacitors don't change the crystal's resonance frequency either yet no one here argues that's a way of adjusting the rate.
> 
> The best I could find about the subject in a few minutes are this:
> http://www.leapsecond.com/pdf/an200-2.pdf
> http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=GetTRDoc.pdf&AD=ADA508100


We have discussed how varying the capacitance of the circuit changes the apparent frequency of the circuit. It is in the electronics and, indeed, it does not alter the crystal's frequency, only the apparent frequency.

But I am at a loss to connect an analog analysis of amplitude variations (in the crystal due to voltage variation) with a digital counter circuit. In my experience counters only trigger on a leading edge - the amplitude of the waveform is inconsequential (assuming it meets the trigger threshold) as is its duration. Since most crystals drive RF-type circuits, the amplitude may be more important to them.

But even accepting that it is important, the HP paper indicates voltage variations are more than an order of magnitude less important than temperature variations and have 1/3 the effect of crystal aging (Fig 27 of the HP paper - the data at the bottom of p. 22 appears to be a misprint).

So I don't see how it can be the source of the 'drift'... but we talk and discuss and learn here. And I have learned a great deal here!

The HP paper is a real find. I don't think we have seen it before. Thanks for digging and finding it!! I'm going to try to attach it to this post for 'safekeeping'


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## South Pender

Eeeb said:


> The HP paper is a real find. I don't think we have seen it before. Thanks for digging and finding it!! I'm going to try to attach it to this post for 'safekeeping'


What I found most interesting in the HP paper is the estimate re crystal aging. If we carry out this factor to 9 months (rather than the 3 tabled), it would seem to account for a greater effect on accuracy than does temperature variation (in the RTXO configuration; in the TCXO configuration, this would happen at more like 5-6 months). This seems contrary to what we have read in accuracy reports. Perhaps the effects of aging are pretty much spent by the 3-month point (although the author talks about "after calibration," rather than strict crystal age), so that those movements that use pre-aged crystals are more immune to this effect than are non-pre-aged crystals. Still, the long-term effects of crystal aging would seem to need serious consideration, and, perhaps, strategies for their control and reduction.


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## McAllan

Eeeb said:


> But even accepting that it is important, the HP paper indicates voltage variations are more than an order of magnitude less important than temperature variations and have 1/3 the effect of crystal aging (Fig 27 of the HP paper - the data at the bottom of p. 22 appears to be a misprint).


One thing I miss in the paper. What about the tuning fork a.k.a. XY cut? After all that is by far the most used crystal cut in practically all watches today and majority of clocks. Tuning forks are inferior to other cuts in many ways. Although they're the only cut to achieve low frequency in a small size.
So that's also why most high precision clocks used the high frequency 4.19 MHz AT cut. The increase in stability wasn't all about the frequency increase but others factors as well. But today manufacturers of high quality watches/whatever need a quartz oscillator have learned to overcome the short comings of the AT cut - probably the best example here of is the DS32KHz oscillator. So what's also interesting is - have the watch manufacturers build in any compensation and if what types and how well do they compensate?

I still do find the variation of the mentioned clocks I have quite apparent. Temperature can't explain the variance I see from a full to an almost empty battery and the change is as sudden as changing the battery and with same temperatures. But perhaps on those it's there also the factor of the circuit itself which (just thinking loud) could shift phase with supply voltage and therefore act like adjusting load capacitors. Whether and how much that's a factor in higher grade movements are a good question. But I think the low supply voltage might be a limiting factor of compensation to voltage compensation.

Anyone has other suggestions?


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## South Pender

McAllan said:


> But perhaps on those it's there also the factor of the circuit itself which (just thinking loud) could shift phase with supply voltage and therefore act like adjusting load capacitors. Whether and how much that's a factor in higher grade movements are a good question. But I think the low supply voltage might be a limiting factor of compensation to voltage compensation.
> 
> Anyone has other suggestions?


If you're suggesting that voltage variation may affect thermocompensation schemes (it's possible I'm misreading you here), this is unlikely, I think, since no watches to my knowledge do temperature compensation via voltage adjustments (I believe the long-discontinued Rolex 5035 movement used this method).


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## McAllan

South Pender said:


> If you're suggesting that voltage variation may affect thermocompensation schemes (it's possible I'm misreading you here), this is unlikely, I think, since no watches to my knowledge do temperature compensation via voltage adjustments (I believe the long-discontinued Rolex 5035 movement used this method).


No. Not anything specific. But I presume it should be well known that varying supply voltage influences every electronic circuit. You can however design it so that it overcomes this but depending on a lot of things that could complicate things a lot if possible at all.

Lets take an LED low energy bulb as an example or just about anything else non low consumption device. It's very easy to make a circuit which within a range - that can even be both lower and higher than the LED voltage - can drive the LED at exactly the required level. It's no issue the circuit uses a little energy as it's barely noticeable compared to the LED itself. In a watch on the other hand there are lots of things against you. Perhaps the most important one - power consumption - so making a switch mode power supply to deliver a constant voltage to the clock circuitry is out of the question. To a certain point a plain old voltage regulating method can be used but there are limits for that too.
So really there tons of things to be aware of when designing a circuit if you want it to be insensitive of different supply voltages (within limits).


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## Sabresoft

Todays updated graph and numbers (we're now at 139 days, 48 for the C70):

















The drop in projected SPY may be influenced by the generally cooler temperatures that we are experiencing of late. It's getting cooler outside and we don't have our furnace turned on right now, so over night the bedroom does get fairly cool, and the daytime highs are lower (except next week when we are supposed to get some summer like daytime temperatures).

Assuming that I adjust the watches after 1 year (Seiko, Breitling, Miros & C70) or at DST/non-DST time change (Precisionist & Sinn) the worst that each watch would likely be out is:









That means that along with my radio controlled watches I currently have at least 6 watches that will be within +/- 10 seconds accuracy at any given point in time. And one more, the precisionist that will be within +/- 15 seconds.


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## jel

Nice and interesting work Sabresoft! I follow your thread with great pleasure while I'm in a similar procedure myself. I've had 6-7 watches on the test-bench for just over 6 months now, three of them identical to yours:
Sinn UX
Breitling Airwolf 
Chris Ward C70
In due time results will be presented, and I will try to adopt your methodology. For now just a comment on this statement:



Sabresoft said:


> I am 121 days into my test and will continue monitoring until 365 days have passed (the Sinn and Precisionist will end the test at the fall time change as their seconds/minutes hands are affected when changing the time). The other 3 can adjust the hour hand independently.


I ran in to the same problem last spring on DST-day, and decided to use this work-around: 
Immediately before setting for DST I did an accuracy-test and then another just after the watch was set for DST.
I then correct all test-results after the DST-setting for the difference between the two readings. In this way I get continuous results also for watches without an independent hour-hand.


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## Sabresoft

Day 146 (55 for the CW C70). The chart doesn't look too different from last time, so I'll just post the projected SPY values:

View attachment 511629


As most claimed SPY performances from manufacturers require a certain amount of wrist time I'm sure that the watches would perform better if worn daily. I'd try wearing only one watch for an extended period, but just can't bring myself to ignore all the other watches for so long. And no I won't wear two watches just for the sake of "science".

That said this test was intended as a "practical" test of a collection of watches to see which will keep the best time while not in use, so that when I wear them they are reasonably accurate.

At this point I have six watches that I can wear on a moment's notice and be confident that they are within +/- 10 seconds or better at any given point in time (assuming a once-a-year reset at minimum):

- Citizen Skyhawk AT (radio controlled)
- Citizen Attesa ATD53-3081 (radio controlled)
- Casio G-Shock GW3500B-1A (radio controlled)
- Breitling Airwolf Raven
- Sinn UX (necessary resets at DST changes will keep it under 10 seconds)
- Christopher Ward C70 Brooklands

The Precisionist is close (as it would have to be reset at DST changes).

I'll need to look into getting the Miros adjusted.

I am looking to eliminate some watches from my current total of 15. The Seiko and Precisionist keep coming under consideration, but I just keep saying no to letting them go. Although the Seiko is non-HEQ it keeps a place in my heart because it has a perpetual calendar and is ana-digi, my favourite format (I have 5 ana-digi watches). The Precisionist might go if Bulova comes out with a model with more complications or even just a perpetual calendar and adjustable hour hand.

While I am not a fan of pure digital watches, the Seiko Brightz SDGA003 does have some attraction for me (solar, RC and EPD display) picture courtesy of Seiko, and would add that "fourth" RC watch to my collection.

View attachment 511674


Then I'd have 4 TC, 4 RC, 1 Precisionist (the accuracy brigade) and 4 standard quartz and 3 mechanical. Of the standard quartz, one, my Independent is up for sale, the Seiko is on the fence right now and the Campanola and non-AT Citizen Skyhawk are keepers. The non-AT Skyhawk was my only watch for 10 years and it was when it went in for maintenance (the pushers needed de gunking) that this horology virus hit me. Of the mechanical watches one, a du Bois, was a gift from my grandfather and stays in the collection, another is a cheap Chinese no name which I kind of like despite the lousy accuracy, and the last is a Rotary with annual date (it doesn't understand leap years), but has too small a dial so it too will be up for sale soon. I'd like to add a Breitling Navitimer or Sinn 903 (similar look to the Navitimer at ½ the price), and am always on the lookout for TC watches.


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## Sabresoft

jel said:


> I've had 6-7 watches on the test-bench for just over 6 months now, three of them identical to yours:
> Sinn UX
> Breitling Airwolf
> Chris Ward C70


Out of curiosity what are the other 4 watches?


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## jel

Sabresoft said:


> Out of curiosity what are the other 4 watches?


They are:
- Seiko SBCM023 (caliber 8F35, from 2010) 
- Seiko, possibly a SLT023 or similar (caliber 8F56, from about 2001) 
- Omega Constellation (caliber Omega 1860 / ETA 252.511, from about 2005) 
- Tissot T-touch, ordinary quartz, but quite accurate so I decided to give it a test.

I also had a Breitling Colt Oceane (caliber Breitling 77 / ETA 956.652) on the bench, but gave it up. Mainly because it belongs to my wife.


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## webvan

McAllan said:


> But I guess there's a factor overlooked. The voltage level. Most clocks and watches speeds up with decreasing voltage level unless they contain compensation for that too.


Good point and this is exactly what happened with my Breitling Aerospace last year that started speeding up (went from 9spy to 55spy) to a point where I got concerned it had become faulty...and then I got the EOL signal. I replaced it (tiny, tiny screw for the battery cover...) and it immediately went back to 9spy when worn.

With the Miros having a rated battery life of 44 months without the chrono and of 23 months with the chrono running at all times, given that they were apparently built in 2008 their batteries could well be nearing EOL.


----------



## Sabresoft

Data update from this weekend (day 153).

I have changed the way that the trendline is calculated. Previously I used the last 8 or so readings. I have now decided to use all but the first few readings, but including zero and this has changed the lines slightly. I decided to eliminate the first three or so readings because small errors on early readings were having a magnified distorting effect on the trend.

The effect of this change was to bring the trendlines more in alignment with the projected SPY values computed by taking a reading and projecting the SPY based on the 365/[email protected] ratio. The upshot of this is that the Precisionist and Miros are now projecting close and within COSC limits respectively.









While most of the trendlines are straight, the Miros line has a bend downwards and then goes straight (which is the projected portion) so I am certain that there is something strange going on with that watch. But I am less inclined to believe that it is due to any fundamental problem with the watch and am tending toward the failing battery theory. While I acquired the watch in April of this year, the COSC certificate was dated July 24, 2008. Although I believe that only the mechanism is tested, I imagine that assembly and mating with the current battery would have happened some time in 2008, which puts the battery at around 3 years old (probably close to it's limit). The ML manual is notably unhelpful in this area, but the CW 70 which also uses the ETA 251.232 caliber has an expected battery life of 2 to 3 years, and the Breitling Avenger Seawolf Chrono which I believe is also based on the same 251.232 caliber also indicates a 2-3 year battery life. I will let this play out, but I wouldn't be surprised to see the battery die shortly. The certificate showed 0.03 SPD at 23C, which would support a 10-11 SPY value, and the Miros was projecting less than that in the first 106 days. It was after that this acceleration effect showed up.

The table below shows the projected SPY from the trendlines, including the old and new methods for this period.









A little further reading and I am now totally confused. The ML uses not the 251.232, but a 251.262, which the ETA website lists as a Flatline not a Thermoline. Yet I have a COSC certificate and the watch has COSC on the dial.


----------



## McAllan

This thread has evolved to be exiting! b-)

Please lets us know what happens to the accelerating Miros! It wouldn't surprise me a bit if the battery is almost done and it jumps back to normal with a new one.

Or you could of course also just have it changed now and see what happens. 
If it doesn't get better instantly you can always send it back for repairing afterwards. ;-)


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## Sabresoft

Day 167

Latest Chart









Latest SPY Summary









Since I suspect that the Miros misbehaviour may be due to near end-of-life battery behaviour I have been running the chronograph continuously 24-7 to expedite final battery failure. We'll see what happens.

As my chart/table doesn't fully identify the models, here is a refresh on the models under test:

- Seiko Worldtime Flightmaster SNJ017 (Standard Quartz)
- Breitling Airwolf Raven (TC)
- Sinn UX (TC)
- Maurice Lacroix Miros Diver Chronograph (TC)
- Bulova Precisionist Claremont (Precisionist High Frequency Standard Quartz)
- Christopher Ward C70 Brooklands (TC)


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## Sabresoft

Day 174, getting pretty close to ½ year.

Just the summary table today.









As mentioned earlier the old method involved using only the later data, the new method included zero and used all the data except for the first few readings (too erratic due to the high error potential in the small readings).

Clearly the Breitling Airwolf Raven and Christopher Ward C70 are showing exceptional performance, the Sinn UX a little less so, but still quite acceptable (Sinn makes no other claims other than COSC Chronometer which this unit easily meets).

The Bulova Precisionist is at around 26 second SPY, just outside COSC, higher than their claimed 10 SPY, but I believe that that requires wearing daily, and actually this watch gets limited wrist time, so the performance is probably acceptable.

The Seiko Flightmaster is a non-TC, non-HEQ watch, and so the 40 SPY performance is quite exceptional considering that standard quartz can be up to +/- 180 SPY.

The Maurice Lacroix Miros continues to "accelerate". I have been running the chronograph 24-7 lately in the hopes of running the battery down quicker, as it is very likely 3 + years old which should be its limit.

Just out of curiosity I looked at the COSC certificates for the TC watches:

The Breitling certificate has no data.

The CW certificate (2010-07-12) has 0.01 spd @ 23°C, 0.05 spd @ 8°C and 0.06 spd @ 38°C - My current measurements indicate a range of 0.0095 to 0.0170 spd (in a temperature range of probably 16°C - 28°C).

The Sinn certificate (2008-02-20) has 0.01 spd @ 23°C, 0.01 spd @ 8°C and 0.02 spd @ 38°C - My current measurements indicate a range of 0.0360 to 0.0365 spd (in a temperature range of probably 16°C - 28°C).

The ML certificate (2008-07-24) has 0.03 spd @ 23°C, 0.02 spd @ 8°C and 0.07 spd @ 38°C - My current measurements indicate a range of 0.0669 to 0.0772 spd (in a temperature range of probably 16°C - 28°C).

Curious that the Sinn and ML are showing current performance at 2.4 and 3.6 times the original tested values @ 23°C. Could this be due to crystal aging?


----------



## South Pender

Nice data, Sabresoft. I don't know whether you have the C70 and Precisionist data in your table because, on my screen, it seems to be truncated after the Miros results. Just to refresh my memory, let me ask you this: In your latest _spy_ estimates have you simply taken the actual drift over the 174 days and multiplied this by 365/174 to get the _spy _values? To me, those would be the most accurate _spy_ estimates with your data.

Your question about the possibility of crystal aging is an interesting one. I have noticed the same phenomenon with my three Grand Seiko 9F models, with later timings indicating larger estimated _spy_ values than earlier timings did (and, I believe, independently of weather-caused temperature changes), although still within specs. It would be good if we could do some accurate modeling of crystal aging. With two of my GS 9Fs, Seiko offer to re-tune them in the third year of use. This might be tacit acknowledgement of crystal aging. I guess our hope would be that if it has to occur, its effects are fairly rapid with a steadily decelerating function, so that by Year 2 or 3, it is in full plateau mode. This all might suggest that we not worry too much at first about accuracy, getting serious by, say, Year 2 and making sure that any re-calibration takes place no sooner than that.

Just out of curiosity, how many trial replications are you averaging to get your drift values?


----------



## Hans Moleman

Sabresoft said:


> Curious that the Sinn and ML are showing current performance at 2.4 and 3.6 times the original tested values @ 23°C. Could this be due to crystal aging?


Yes that is surprising. 
And why didn't it happen for the Breitling? Assuming of course that it was delivered at 0.01 spd?

Another good reason to demand adjustment facilities on the movement.


----------



## Sabresoft

South Pender said:


> I guess our hope would be that if it has to occur, its effects are fairly rapid with a steadily decelerating function, so that by Year 2 or 3, it is in full plateau mode. This all might suggest that we not worry too much at first about accuracy, getting serious by, say, Year 2 and making sure that any re-calibration takes place no sooner than that.


Well the ML & Sinn are 3 years old based on the COSC certificates. I can live with the Sinn (I'd prefer under 10 SPY, but then I have to reset it twice a year for DST/non-DST due to there not being a quick hour feature, so the worst it will be out is about 8.5 seconds).

I am not sure that battery is the problem on the ML, but it seems to be a feasible explanation considering its probable age (I doubt that the vendor would have replaced it, so I am assuming that it dates from when the unit was first assembled). If so then the true normal multiple of original drift may be much lower. We'll see.




South Pender said:


> Just out of curiosity, how many trial replications are you averaging to get your drift values?


I take six readings, and then if one or two are extreme (say one high, one low) I'll throw those out and take two more readings.

For example the last readings for the Breitling were:


1.531.511.511.51.541.5

for an average of 1.515 (I used 1.52 in my SPY calc). These values were the difference between the time that I started timing on the tested watch and the point where the reference source passes 5 seconds later).

I then compute the actual difference as:

measured average reading minus 5 seconds minus initial offset at time of starting the test

so in the case of the Breitling the actual difference is: 1.52 - 5 - (-0.35) = -3.13 seconds

and in the case of the ML it is: 17.44 - 5 - (-0.55) = 12.99 seconds

Even if I used 1.5 or 1.54 this time for the Breitling the projected SPY would fall in a range of 6.39 to 6.40 per the trendline.

What I did not do was take multiple readings when capturing the initial offset. The next time I launch a test I will take more care in establishing the initial offset (which ranged between -0.55 and +0.39 seconds for the various watches in this test).

The general fluctuations in my readings (including the initial offsets) is a testament to my poor hand-eye coordination, and my slow reaction time. Still for the most part there is a consistency in the periodic readings that shows an SPY projection that is fairly consistent from week-to-week. With the exception of the ML, which shows a continual growth.

I don't think that procedural errors in my method could explain the ML situation, because if my procedure was flawed other watches would also be showing strange behaviour, and they aren't. Doing the readings for the ML is more challenging than for most of the others because of the short, but fat seconds hand (the same caliber CW has a much thinner seconds hand and a tick for every second, not 5 second increments, so it is much easier to do the readings). Also the alignment of the ML seconds hand is poorer, and so when I do readings I tend to get ⅓ to ½ with a full second difference from the others. As a result I may do 10 or more to get a consistent sample of 6 actual readings that I use in my average.


----------



## South Pender

Sabresoft said:


> Well the ML & Sinn are 3 years old based on the COSC certificates. I can live with the Sinn (I'd prefer under 10 SPY, but then I have to reset it twice a year for DST/non-DST due to there not being a quick hour feature, so the worst it will be out is about 8.5 seconds).
> 
> I am not sure that battery is the problem on the ML, but it seems to be a feasible explanation considering its probable age (I doubt that the vendor would have replaced it, so I am assuming that it dates from when the unit was first assembled). If so then the true normal multiple of original drift may be much lower. We'll see.
> 
> 
> 
> I take six readings, and then if one or two are extreme (say one high, one low) I'll throw those out and take two more readings.
> 
> For example the last readings for the Breitling were:
> 
> 
> 1.53
> 1.51
> 1.51
> 1.5
> 1.54
> 1.5
> 
> 
> for an average of 1.515 (I used 1.52 in my SPY calc). These values were the difference between the time that I started timing on the tested watch and the point where the reference source passes 5 seconds later).
> 
> I then compute the actual difference as:
> 
> measured average reading minus 5 seconds minus initial offset at time of starting the test
> 
> so in the case of the Breitling the actual difference is: 1.52 - 5 - (-0.35) = -3.13 seconds
> 
> and in the case of the ML it is: 17.44 - 5 - (-0.55) = 12.99 seconds
> 
> Even if I used 1.5 or 1.54 this time for the Breitling the projected SPY would fall in a range of 6.39 to 6.40 per the trendline.
> 
> What I did not do was take multiple readings when capturing the initial offset. The next time I launch a test I will take more care in establishing the initial offset (which ranged between -0.55 and +0.39 seconds for the various watches in this test).
> 
> The general fluctuations in my readings (including the initial offsets) is a testament to my poor hand-eye coordination, and my slow reaction time. Still for the most part there is a consistency in the periodic readings that shows an SPY projection that is fairly consistent from week-to-week. With the exception of the ML, which shows a continual growth.
> 
> I don't think that procedural errors in my method could explain the ML situation, because if my procedure was flawed other watches would also be showing strange behaviour, and they aren't. Doing the readings for the ML is more challenging than for most of the others because of the short, but fat seconds hand (the same caliber CW has a much thinner seconds hand and a tick for every second, not 5 second increments, so it is much easier to do the readings). Also the alignment of the ML seconds hand is poorer, and so when I do readings I tend to get ⅓ to ½ with a full second difference from the others. As a result I may do 10 or more to get a consistent sample of 6 actual readings that I use in my average.


I don't think there's anything wrong with your procedures. In fact, the six values you gave for the Breitling show a standard deviation of only .016 sec. This is very, very good, and better than I usually get (my standard deviations tend to be around .025 - .035 sec.), and indicates excellent eye-hand coordination and reaction time. Your point about running a large number of timings in the future to establish initial offsets is right on the money. Since this initial offset is the basis for all future drift estimates, it is important that it be the most accurate. I'd run _at least _20-30 timing trials to establish this baseline.

In addition, trimming off outlier observations is good practice. We label averages so calculated _trimmed means_, and this is considered good statistical practice. I usually trim off the upper and lower 10% of my trial observations (to avoid bias, you should trim the same number from each tail of your distribution), but I don't replace them. Trimming will significantly lower your standard deviations and reduce the random-error component of your measurements.


----------



## Sabresoft

Well we're almost at 6 months (181 days, 90 for the C70):









The Sinn, Airwolf and Precisionist continue with very similar projected SPY values. The Seiko seems to be improving a little. I wonder if this is due to the generally cooler temperatures of late.

The Miros continues to show an increased SPY projection. Still waiting for the battery to die. The C70 is also showing a slight increase in SPY projection from week-to-week, but the line still looks to be relatively straight unlike the Miros which is showing a decided upwards curvature.









The rather strange shape of the Seiko and to some extent the Miros curves is partially due to limitations of the Excel trendline function. I am not too worried because as we get closer to 365 days these lines will make more sense.

Considering that I do not wear the Precisionist very much I think that the 26 SPY is acceptable. I'm sure that if I could wear it daily I'd see closer to the claimed 10 SPY, although I'm not sure it would be 10.


----------



## South Pender

It will be interesting to see whether there is any change to your trend lines as the weather gets distinctly colder. This will only have an effect, of course, on those you wear outdoors. All things considered (cost, etc.), that seems like pretty decent performance for the Precisionist.


----------



## Sabresoft

South Pender said:


> It will be interesting to see whether there is any change to your trend lines as the weather gets distinctly colder. This will only have an effect, of course, on those you wear outdoors. All things considered (cost, etc.), that seems like pretty decent performance for the Precisionist.


I don't anticipate too much difference from the temperature outdoors because in the winter the watch is inside my winter jacket sleeve and with the possible exception of a long session shoveling snow I wouldn't expect my arm to get too cool. Most of the time it will be short durations outside.

The bigger impact though may come from inside temperatures because we allow the bedroom to cool significantly during the overnight and daytime hours, only running heat when we are getting up and getting ready for bed. It is not unusual to have the temp at 18C and during the really cold weather it can even drop to 16C.

The sudden change in the Seiko lately may be due to the already cooler daytime and overnight temperatures.


----------



## Sabresoft

Day 188

The latest chart:









Noticeable is the truncated line for the Seiko. There is a reason for this. As of Yesterday I no longer own that watch. I had been on the fence about selling the watch over several months now.

Reasons to sell:
- Not HAQ
- No backlighting of the digital display
- Didn't get much wrist time because in many ways was too similar to the Breitling and Skyhawk in style

Reasons not to sell:
- Ana-digi style (which I like)
- "pilot" style watch with slide rule bezel (another of my favourites)
- Perpetual calendar
- Multiple complications (chronograph, world time, alarm)
- Pretty good accuracy for a non-HEQ

Reason it sold: was showing a picture of my collection to a co-worker on Wednesday and he pointed to it and said he quite liked it. Impulsively I asked if he wanted to buy it and he said yes. In some ways I miss it already, and I was curious to see where the curve was heading (I almost wanted to say wait till Monday so that I could do one more reading at least), but as pointed out in the reasons to sell above, it just wasn't getting much wrist time, and as far as I am concerned my collection has to be a "wearing" collection, not just something that gathers dust in a drawer.

The SPY data:









The Breitling, Sinn, Precisionist and CW C70 are showing fairly consistent SPY projections, (the C70 with a little growth but seems to be stabilizing). The Miros continues its upwards projection well outside COSC.

The plan forward is to continue the test till next April for the Breitling, CW and Miros (assuming no battery failure), and to start a new test after the no-DST time change for the Sinn, Precisionist and add in my non-AT Skyhawk. Probably do an update on each test on alternating weeks.


----------



## Hans Moleman

Sabresoft said:


> ... it sold ...


It did a great job as a thermometer.
Your testing showed that the Seiko was calibrated very well: The rate seems to be positive as well as negative depending on temperature.

Keep up the good work.


----------



## panamamike

Excuse my ignorance,but what is a spy?
How do I measure a spy on a watch?
Does it require a sub second hand?

Mike


----------



## McAllan

panamamike said:


> Excuse my ignorance,but what is a spy?
> How do I measure a spy on a watch?
> Does it require a sub second hand?
> 
> Mike


spy = Seconds Per Year.

For measuring accuracy take a look at this thread.

Hope this clears up things


----------



## panamamike

McAllan said:


> spy = Seconds Per Year.
> 
> For measuring accuracy take a look at this thread.
> 
> Hope this clears up things


That certainly does, thanks for the help.

Mike


----------



## Sabresoft

panamamike said:


> Excuse my ignorance,but what is a spy?
> How do I measure a spy on a watch?
> Does it require a sub second hand?
> 
> Mike


As McAllen explained, SPY is of course seconds per year the way that we usually rate HEQ watches. It does require a second hand or digital seconds display.

Actually different types of watches rate on different types of periods.

Standard quartz usually rate on seconds per month (SPM). Most standard quartz usually rate at +/- 10-15 SPM. Some lower grade are as bad as +/- 20-30 SPM.

Mechanical watches rate on seconds per day (SPD). Swiss Chronometer grade mechanical watches (COSC = Contrôle Officiel Suisse des Chronomètres) must meet or better +6/-4 SPD. COSC requirements for chronometer grade quartz watches are +/- 0.07 SPD (corrected from earlier where I typed 0.7) or 25.5 SPY.

Most thermocompensated quartz calibers currently on the market fall in the +/- 5-15 SPY range (Seiko 9Fxx, Citizen A660 and various ETA calibers). Thermocompensation (TC) is what differentiates HEQ from standard quartz as quartz crystals are temperature sensitive.

Mechanicals while also being affected somewhat by temperature are much more affected by physical position (due to gravity affects). This is also why mechanical watches can have reasonably good performance because while a watch may gain on the wrist it may lose on the night stand or visa versa for an average daily performance that can be quite reasonable.

But overall true HEQ accuracy is hard to meet with anything other than a TC caliber.


----------



## McAllan

Sabresoft said:


> Mechanical watches rate on seconds per day (SPD). Swiss Chronometer grade mechanical watches (COSC = Contrôle Officiel Suisse des Chronomètres) must meet or better +6/-4 SPD. COSC requirements for chronometer grade quartz watches are +/- 0.7 SPD or 25.5 SPY.


You mean +/- 0.07 SPD for chronometer grade ;-)


----------



## dwjquest

Sabresoft said:


> As McAllen explained, SPY is of course seconds per year the way that we usually rate HEQ watches. It does require a second hand or digital seconds display.


This is true only if you use the hand timing method. I have timed many watches that do not have a seconds hand. Some that move the minute hand once every 15 sec., once per minute, etc. To do these timings, you need to use a timing machine.


----------



## Catalin

panamamike said:


> Excuse my ignorance,but what is a spy?
> How do I measure a spy on a watch?
> Does it require a sub second hand?
> 
> Mike


That's why I always use s/y (or eventually seconds/year first time in a long post and when s/y later).


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## Sabresoft

McAllan said:


> You mean +/- 0.07 SPD for chronometer grade ;-)


Yes, good catch, thanks.


----------



## Sabresoft

Day 195 (104 for CW C70)

The latest chart of projected (via trendline) SPY values:









I have added a days-in-test (vertical) line to show the division between actual (to the left) and projected (to the right) values for the main test (4 watches, the CW C70 is actually 91 days behind the others).

The Breitling, Sinn, Christopher Ward and Precisionist are showing fairly steady lines. The Miros continues to speed up, projecting a worse SPY each week. I have the chronograph running continuously so the battery should die fairly soon now (I hope) because the off-spec behaviour has been happening for almost 3 months now!

The Seiko was just starting to get interesting (seasonal temperature effects I assume) and then I had to go and sell it! Seller's remorse I guess.

The latest table:









The Sinn and C70 are showing gentle increases over time. Could this perhaps be due to crystal aging?

Just for fun I decided to revisit and modify my original chart that shows estimated SPY at reading date rather than the actual offset at each date with a trendline projection to 365 days. The revisions to this chart include lines defining + and - COSC limits, and a vertical line representing current reading date. I have also removed the trendline projection out to 365 days.









This chart clearly highlights the accelerating behaviour of the Miros, the (assumed) temperature response of the Seiko, and the generally flat behaviour of the other 4 watches. There was a small growth in the early stages of the Precisionist (crystal aging perhaps).

For those readers of this thread who may not be familiar with all the watches in the test, here is a gallery showing the candidates:

Seiko Worldtime Flightmaster (SNJ017) (Left) and Sinn UX (Right)















Maurice Lacroix Miros Diver (left) and Christopher Ward C70 Brooklands COSC (Right)















Bulova Precisionist Claremont (Left) and Breitling Airwolf Raven (Right)


----------



## South Pender

This is very informative. One thing that jumps out from your tabled results is the stability of the Bulova Precisionist over a considerable period of time. If I'm reading your results correctly, this watch demonstrated a drift rate of about +20 _spy_ after 50 days. This went up to maybe +23 _spy_ at 100 days (not much change), and seems to be plateauing at about +26 _spy _from about 120 days to the present 195-day mark, a period of 2 1/2 months. Given the rock-bottom price of this watch, I would give it high marks for accuracy, which is very close to the COSC standard of +/- 25.5 _spy_, and considerably superior to that of the much more expensive Miros, a watch advertised to meet the COSC standard. This very gentle rise in _spy_ and eventual flattening suggests a negligible crystal-aging effect. I particularly like the realistic nature of your test, in which you have nicely simulated a common wearing pattern with owners of more than one watch--on the wrist one day, off for a couple, back on, etc.


----------



## Sabresoft

South Pender said:


> . . . and considerably superior to that of the much more expensive Miros, a watch advertised to meet the COSC standard.


The Miros was showing fairly steady (and COSC worthy) performance in its early days with me and then suddenly one week started shooting up. I am fairly convinced that battery death throws are to blame, because I believe the battery is over 3 years old. I suppose I could just change it now and see if the performance returns to spec.



South Pender said:


> . . . in which you have nicely simulated a common wearing pattern with owners of more than one watch--on the wrist one day, off for a couple, back on, etc.


Probably more than a couple days off though with the collection that I currently have (13 watches right now). But, yes that was the purpose of my test, to see how the watches perform from a grab and go perspective so that I could put one on on any given day and have confidence that it was reasonably accurate.

I have set a criteria of acceptance of within 10 seconds. Currently the Breitling, and CW C70 meet that on an annual basis (I am assuming that I'd do a reset at year end). The Sinn does, as it has to be reset at DST start/end so at worst it will be off by about 8 seconds. The Precisionist is close, again based on DST changes. Hopefully I will be able to get the Miros in line again too.

The above combined with my three RC watches (Skyhawk AT, Attesa and G-Shock) gives me at least six high accuracy watches (seven if the Miros turns out to be OK).


----------



## McAllan

That change really made a difference. Displaying the sec/year instead of the less interpretable offset.

One thing I noticed the others didn't mention is that the Sinn and Breitling curves are quite similar. Yes offset and while not 100% identical but still very similar.
Guess this is because they're both relying on ETA movements. Perhaps they're not using 100% identical algorithms but none the less they're quite similar.


----------



## Sabresoft

Actually the CW C70 is also parallel too as it sits right on top of the Breitling curve. I am hopeful that once I replace the battery the Miros will also run parallel too. Maybe I won't bother waiting for the battery to die and just go and get it changed. Then at least I'll know for sure if it is the battery or the watch itself. Maybe next weekend I'll get it changed and start a new test with the Miros, the Sinn and Precisionist (due to DST change) and bring in my non-AT Skyhawk as the non-HEQ now that the Seiko is gone.


----------



## Sabresoft

Day 201 (110 for CW C70)

Well the big news is that the Miros' battery died between yesterday (when I wore it last) and tonight when I went to do my testing. It must have really speeded up at the very end because the date showing was the 6th, and it is only the 4th today, and was correct yesterday!

The Days-in-test/offset chart:









The SPY estimate at day in test chart:









And the table of projected SPY values:









So it's off to get a new battery for the Miros tomorrow, and then on Sunday I will start a new test with the Miros, non-AT Skyhawk, and the DST adjusted Sinn and Precisionist.

The current test will continue (probably on alternating weeks) with the Breitling and CW C70.

At this point the Breitling, Sinn, C70 and Precisionist all seem to have fairly consistent behaviours:
- gently sloped lines on the projected offset vs date chart, trending towards a SPY value at 365 days 
- and flat lines on the chart where the SPY is estimated from each reading


----------



## Sabresoft

So the new test has been initiated (last night), and I have created a chart that shows all the results in a table. The thumbnails of the SPY charts is intended to show a rough idea of the SPY estimates over time, and in the case of the Precisionist, Miros and UX a quick visual comparison of the old and new tests.









I will attempt to update this chart periodically, although the thumbnails are fiddly and time consuming to create so I may not do that every week.


----------



## Sabresoft

I have updated my chart after only 6 days on the new tests. Originally I wasn't going to do that because of the very short data period, but I just couldn't resist. The standard deviation in the test data varied from watch to watch, but if we use an upper bound value of 0.04, the impact on SPY values would be about +/- 2.4 SPY.









While not drawing any conclusions from this early data, basic observations are:

1. The Precisionist is showing behaviour close to what we were seeing in the old test (25.99 SPY, 22.51 + 2.4 = 24.91)
2. The Sinn could be showing similar behaviour to the earlier test (13.43 SPY, 10.34 + 2.4 = 12.74)
3. The Miros seems to be behaving better than before, but it is far too early to jump to any conclusions as the early behaviour in the previous test looked pretty good too, before the rapid growth began.

Still I am fairly convinced that the Miros' earlier misbehaviour was due to the battery, as it gained almost 48 hours in the last 24 hours of the battery's life (i.e. I wore it Thursday and the offset was looking consistent with the previous weeks' gains, when I found the watch was dead on Friday evening the calendar was advanced almost 2 full days).


----------



## South Pender

Sabresoft said:


> I have updated my chart after only 6 days on the new tests. Originally I wasn't going to do that because of the very short data period, but I just couldn't resist. The standard deviation in the test data varied from watch to watch, but if we use an upper bound value of 0.04, *the impact on SPY values would be about +/- 2.4 SPY.*


(Boldface in quote mine.) I don't think you have this quite right. If the standard deviation you are referring to is that accompanying the distribution of timing values you obtained in your test consisting of a number (_n_) of timings using the Stopwatch Method, it is the wrong one from which to set limits around your _s/y_ values. I am assuming that the _s/y _values you are reporting for your watches are based on *mean* timing values of a small distribution of something on the order of 10 timing trials, with each watch at a particular time. If we label the standard deviation you have calculated as _sd_ (and set to a constant value of .040) and the number of timing trials you have run (to obtain your _mean_ value that you report) as _n_, the appropriate standard deviation for describing the limits of your _mean_ offset value is _sd_/_sqrt_(_n_). _Note:_ I couldn't get the square root symbol to transfer to this post, and, thus have used "_sqrt_" instead. Sorry if it makes the expressions needlessly less intelligible.

As an example, if you, in fact, did _n_ = 10 timing trials with the Stopwatch Method, and obtained, say, a *mean offset value* from those trials of .150 sec. (and an assumed _sd_ of .040), a 95% confidence interval would extend from about .121 to .179 sec. This confidence band exists because of measurement error in your offset calculations.

Now consider that when you estimate drift over time, you are taking the *difference between two mean offset values*, one occurring at the baseline observation point and the other at some time period beyond the baseline point, say 3 months later. Each mean offset estimate has accompanying measurement error (as noted above), and the difference between the two has, not surprisingly, greater error than that seen at each time point, because it is arising from two sources of error. In fact, if we take the same number of timing trials, _n_, at each of the two time points, then the error attached to the difference is _sqrt_(2_)sd_/_sqrt_(_n_). As an example, if we further let _sd_ = .040 sec. (a reasonable value to use for this, and one suggesting careful timing), then the error attached to *the difference* (indexing drift) is _sqrt_(2)(_._040)/_sqrt_(10) = .01789 sec.

Let's now take another example, this one enabling an estimate of _drift _over time (our best estimate of _accuracy_ over time). At baseline, you get the mean offset value above, .150 sec. as the offset from perfect time. At Time 2, say 92 days later, you get the mean offset value of 1.25 sec.-offset from perfect time. Thus, your best estimate of drift is 1.25 - .15 = 1.10 seconds of drift over the approximately 3 months. We can then prorate that to the _s/y_ metric by 365/92 X 1.10 or *4.36* _s/y_. However, the error standard deviation is not similarly multiplied by 365/92, but, in fact, is (as noted above) _sqrt_(2)(_._040)/_sqrt_(10) = .01789, capturing as it does only measurement error, and thus not subject to prorating. We could then set a 95% confidence interval for the prorated drift by taking 4.36 ± .038 = a range of about 4.322 to 4.398. (The .038 sec. is approximately twice the standard deviation of the difference between means given above and corresponds to the critical value of the normal-, or, more correctly, Student's _t_-distribution.) Thus, the impact of measurement error on _s/y_ values is no different whether it's applied to a 1-month time-period drift estimate or to a 6-month, or 12-month estimate. The amount of measurement error accompanying the difference between two mean offset values is a constant (assuming similar _sd_ values at the two time points) and not variable as a function of the time period.


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## Sabresoft

South Pender said:


> (Boldface in quote mine.) I don't think you have this quite right. If the standard deviation you are referring to is that accompanying the distribution of timing values you obtained in your test consisting of a number (_n_) of timings using the Stopwatch Method, it is the wrong one from which to set limits around your _s/y_ values. I am assuming that the _s/y _values you are reporting for your watches are based on *mean* timing values of a small distribution of something on the order of 10 timing trials, with each watch at a particular time. If we label the standard deviation you have calculated as _sd_ (and set to a constant value of .040) and the number of timing trials you have run (to obtain your _mean_ value that you report) as _n_, the appropriate standard deviation for describing the limits of your _mean_ offset value is _sd_/_sqrt_(_n_). _Note:_ I couldn't get the square root symbol to transfer to this post, and, thus have used "_sqrt_" instead. Sorry if it makes the expressions needlessly less intelligible.
> 
> As an example, if you, in fact, did _n_ = 10 timing trials with the Stopwatch Method, and obtained, say, a *mean offset value* from those trials of .150 sec. (and an assumed _sd_ of .040), a 95% confidence interval would extend from about .121 to .179 sec. This confidence band exists because of measurement error in your offset calculations.
> 
> Now consider that when you estimate drift over time, you are taking the *difference between two mean offset values*, one occurring at the baseline observation point and the other at some time period beyond the baseline point, say 3 months later. Each mean offset estimate has accompanying measurement error (as noted above), and the difference between the two has, not surprisingly, greater error than that seen at each time point, because it is arising from two sources of error. In fact, if we take the same number of timing trials, _n_, at each of the two time points, then the error attached to the difference is _sqrt_(2_)sd_/_sqrt_(_n_). As an example, if we further let _sd_ = .040 sec. (a reasonable value to use for this, and one suggesting careful timing), then the error attached to *the difference* (indexing drift) is _sqrt_(2)(_._040)/_sqrt_(10) = .01789 sec.
> 
> Let's now take another example, this one enabling an estimate of _drift _over time (our best estimate of _accuracy_ over time). At baseline, you get the mean offset value above, .150 sec. as the offset from perfect time. At Time 2, say 92 days later, you get the mean offset value of 1.25 sec.-offset from perfect time. Thus, your best estimate of drift is 1.25 - .15 = 1.10 seconds of drift over the approximately 3 months. We can then prorate that to the _s/y_ metric by 365/92 X 1.10 or *4.36* _s/y_. However, the error standard deviation is not similarly multiplied by 365/92, but, in fact, is (as noted above) _sqrt_(2)(_._040)/_sqrt_(10) = .01789, capturing as it does only measurement error, and thus not subject to prorating. We could then set a 95% confidence interval for the prorated drift by taking 4.36 ± .038 = a range of about 4.322 to 4.398. (The .038 sec. is approximately twice the standard deviation of the difference between means given above and corresponds to the critical value of the normal-, or, more correctly, Student's _t_-distribution.) Thus, the impact of measurement error on _s/y_ values is no different whether it's applied to a 1-month time-period drift estimate or to a 6-month, or 12-month estimate. The amount of measurement error accompanying the difference between two mean offset values is a constant (assuming similar _sd_ values at the two time points) and not variable as a function of the time period.


Yikes I walked into that one, didn't I. I had to reread your response several times (it has been almost 25 years since I took stats, and other than looking at means and standard deviations occasionally I don't really use stats much in my day-to-day work). But what I was (in a non-rigourous way) suggesting was that had my offset reading
really been at the upper limit of the the 95% confidence limit, then my SPY estimate would have been higher.

Realistically I shouldn't even be playing with 6 day data to estimate SPY. The last test showed that I only started getting stable projections at about 40 days of data. I just couldn't wait. The SPY value that I will be most interested in will be the value calculated at 365 days (possible for 4 of the 6 watches in my test).


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## South Pender

Sabresoft said:


> Realistically I shouldn't even be playing with 6 day data to estimate SPY. The last test showed that I only started getting stable projections at about 40 days of data. I just couldn't wait. The SPY value that I will be most interested in will be the value calculated at 365 days (possible for 4 of the 6 watches in my test).


I know the feeling! I'm struggling to not post some 2-week results with my new Citizen AQ1000-58E. :-d


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## Sabresoft

Day 229 for the Breitling, 138 for the CW C70 and 27 for the new test. The ML Miros & Sinn UX are tending towards the mid teens in the SPY estimates. I am still seeing some instability in the new test data which I expect will settle down after the next few weeks.


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## Sabresoft

Day 237 for the Original Test (Breitling, day 146 for the CW C70)

The two watches are showing fairly steady SPY projections (Breitling -6.85 SPY, C70 -7.59 SPY):

















Day 35 for the new test (Precisionist, non-AT Skyhawk, Miros and UX)

The non-AT Skyhawk is projecting well outside COSC limits as would be expected for a non-TC watch. The Precisionist is hugging the COSC limit much as it did in the first test. The Miros is trending to about 12.39 SPY which is higher than in the early days of the first test, but so far looks to be fairly steady unlike the first test where the readings took off as the battery died. The UX is trending a little higher than in the original test, but not enough to concern me at this stage.









This second test will probably terminate in March at DST time (although I might try doing an offset adjustment at that time, we'll see). At that time I will probably try regulating the Miros. The UX I would have to live with, but as long as it stays within COSC I'll be OK with it due the cost and hassle of shipping it back to Germany.

Overall Summary


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## Sabresoft

Day 250 Breitling (159 CW C70)

The latest test charts for the Breitling and CW C70 show a fairly steady trend for SPY

















Day 48 Precisionist, Skyhawk, Miros, Sinn

The curves are starting to settle down. The offset trend chart for the four watches is shown:










The overall summary table:


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## South Pender

Things are certainly looking much better for the Miros!


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## Sabresoft

But the SPY is higher than it was for the first test before it went crazy (early projection was in the 4 SPY region at 48 days in the old test, it was only at about 80 days that the offset started shooting up as the battery was going through its death throws). I guess that after the battery change the watch needed to be adjusted, which makes sense as the adjustment is by applying a wire across terminals so this adjustment needs to be done under power and would most likely be lost with the battery removed.

The other interesting observation is that the Skyhawk while not shabby at around 36 SPY for a non-TC caliber is still less accurate than I had thought it was from the past where I didn't actually time it. As it is a perpetual calendar and has the ability to switch from DST to ST without adjusting the hour/minute hands manually, theoretically I would not have to adjust it other than to correct for accuracy. I guess I must have tolerated errors of 2 - 3 minutes over a number of years between corrections, now I get "mildly irritated" when my good TC watches are off by 5 seconds. I have mechanicals that can produce that kind of inaccuracy (minutes) within a week, so still not too shabby.


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## South Pender

The other thing that I find fairly impressive is the performance of the Bulova Precisionist. Sure, it's not making its advertised specs of ± 10 seconds per year, but, for the price, its performance is not too shabby. There is also no sign with this specimen of the crystal aging phenomenon written about by others in connection with the Precisionist.


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## Sabresoft

Just to mess things up I decided to adjust the Miros today, and so will restart the test for that watch from today. I gave it 3* pulses so hopefully the offset will drop significantly.

* I'm not sure if the third was a clean contact, so I may have only done 2 pulses, so we will see what happens.

As to the Precisionist, it might be doing better if I wore it more often, but as I have so many other watches and prefer chronos (mainly just for the complications, but also for actual use at times), the Precisionist does not get a lot of wrist time.


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## Sabresoft

Day 257 for Airwolf, 166 for CW C70, 55 for Precisionist, Skyhawk, and UX and 7 for restarted Miros test









The short test period for the new Miros test is probably too unreliable to draw any conclusions, but compared to the previous test, before adjusting, it looks to be doing better. Time will tell if this is realistic.

The Airwolf and C70 have been creeping upwards (numerically) ever so slightly over time. Not sure if this can be attributed to aging as the offset is getting bigger negatively. Still the performance of both is quite acceptable at around the 7 to 8 spy mark.

The Skyhawk is proving to be less accurate than I had assumed from prior use (i.e. not actually measured in the past), but is still not bad at around 36 spy, 3 spm or 0.1 spd, well within standard quartz specifications. But then as I don't wear this watch much anymore it is basically just from stored conditions in the 16ºC to 20ºC (60.8ºF to 68ºF) range. I imagine if worn that the results would change.

The Sinn is settling down with results getting closer to the original test.


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## Sabresoft

Day 265 (Breitling), 174 (CW C70), 63 (Precisionist. Skyhawk and UX), 15 (Miros)

This week I have decided to do something a little different in my update. I took a look at the data for the Breitling Airwolf and CW C70 and played around with it a little.

I decided to plot a curve showing deviation of each week's SPY projection from the average of all the SPY projections for that watch. The horizontal scale shows days, but is actually in effect a date scale, as the days are days since April 17, 2011 when the Breitling test started. The CW C70 curve therefore starts 91 days later than the Airwolf curve.









What I read from these curves primarily, as they seem to parallel each other fairly well, is that the deviation from average of the SPY projections probably shows a week-to-week (or sampling set to sampling set) variability that may be related to one or more of the following:

(a) Variance in my sampling precision from week-to-week i.e. I find that some weeks I have better reaction times than other weeks, not just in general, but also in the sense that I might be triggering the starts and stops inconsistently, so that one week I may tend to start the timer a little sooner, and stop it a little later and do the reverse the following week, and even from watch to watch. I played around with this today and discovered that I could account for as much as 0.03 seconds variance on each end of a timing based on my reaction times. While I take a number of samples and aim for standard deviations in the 0.02 to 0.03 range, that does not guarantee that I am not building in a bias with my hand-eye co-ordination. So one week I may be getting very good STDEVs and feeling comfortable that I have a good offset reading, but the actual interval that I am really measuring could still be different from week-to-week (i.e. one week I might actually be timing a 5.06 second interval and another week a 4.94 second interval, but consider it to be a 5 second interval - I know that the video method would probably alleviate this, but its just too much hassle to do that every week). Even at 250 days that could translate into a misestimate on SPY (assuming say a short interval at start of test, and a long interval at 250 days) of as much as 0.18 seconds. At 100 days that could translate into a SPY misestimate of 0.44 seconds. Even that 0.03 second estimate that I determined for my reaction times today could be wrong. Maybe some weeks it's even more.

(b) Temperature effects

Although TC watches are less susceptible to thermal variations, they are not immune (the COSC criteria is +/- 0.07 seconds per day at 23ºC and +/-0.2 seconds at 8ºC and 38ºC). My temperature range is more like 16ºC to 24ºC, so the variation would be smaller. The original COSC test for my CW showed (-)0.01 seconds @ 23ºC, (-)0.05 seconds @ 8ºC and 0.06 seconds @ 38ºC. From this test the temperature range effects could be in the range of (-)0.031 - (-)0.0065 = (-)0.0245 seconds per day.









Now of course the actual impact on cumulative offset between any two dates would depend on the temperature history between the two dates, and as I have not been doing any monitoring of any temperatures I cannot truly estimate any true impact, but if we were to assume a continuous transition between say date 150 (24ºC) of the total test period (day 59 of CW test) and day 250 (16ºC) (159 for CW), and use half the range calculated above (0.0245/2 = 0.01225) to represent the average effect we could potentially see a difference in offset as follows:

Offset measured on Day 59 of CW test (approx) -1.05 seconds

Projected cumulative offset estimated using average temperature transition (0.01225 seconds), and assuming no other effects on the offset readings: - 1.05 * 159 / 59 + 100 * (-)0.01225 = -4.05 seconds

The difference in estimated SPY values could be as much as:

SPY @ day 59 = -6.50
SPY @ day 159 = -9.30 seconds
Difference = ABS[(-)9.30] - ABS[(-)6.50] = 2.80 seconds variation in SPY estimates, due to the assumed temperature history.

Looking at the first chart, the range for the CW between day 150 and day 250 (59 and 159 respectively in the CW test) could be roughly ABS[1.5]-abs[-0.5] = 2.0 seconds, so it is not inconceivable that the variation in temperature could be having some effect on the variation from the average SPY estimate, and of course as the real temperature behaviour is up and down within each day and between days, that would go a ways to explaining some of the test-to-test variation.

None of this is precise, because of course the average itself is contaminated by any bad sets of readings (i.e. a particularly bad hand-eye co-ordination day for me, especially early in the test), and as there has been no control for temperature effects, all of the above is purely speculative, but as they say in economics, ceterus paribus (all else being equal) the impacts of the two phenomena I have identified can probably explain a lot of the test-test variations that I am seeing.

What I am not seeing supported by that curve is aging effects.

The next chart shows the variance from the average of the SPY estimates divided by the number of days at that variance date (shown in milliseconds as seconds would be too coarse (i.e. you'd see a straight line). In this case each curve is plotted based on the number of days in the test for that watch.









What I get from these curves is the following:

(a) As we already intuitively know, early readings cause much greater variability in SPY estimates due to the magnified impact of small errors;

(b) The downward slope of both curves once they settle down might suggest aging effects, although I am not clear in my mind if aging effects can go both ways (i.e. Slow watches run slower and fast watches run faster (both these watches are running slow). I suspect not, and am open to other interpretations.

All of the above is just me playing around with my data to see if there are any discernible patterns. Of course it all could just be a lot of iffy data collection on my part, and so I would not draw any hard conclusions from the above, but it has sure been a fun way to waste a Saturday morning.


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## South Pender

As always, interesting data and some interesting interpretations. Frankly, I think that you have overemphasized the "variance in sampling precision" explanation. If there are reaction-time differences from week to week, these should manifest themselves at both ends of the timing procedure (at the beginning with the starting of the stopwatch on the reference clock and the end with stopping it on the minute marker of your watch). A while back, I talked with a colleague of mine, who is a cognitive science scholar, about whether reaction time should differ between a response to a number on the reference clock and that to a marker on a watch dial, and his opinion was that it shouldn't. This means that, since you are taking the _difference_ to get your offset value, this offset estimate should be largely unaffected by weekly variations in your alertness and reaction time. You've mentioned the phenomenon of, in a particular week, starting a little too soon and ending a little too late. This seems very unlikely to me, and far less likely than being off the same way (starting and stopping) in a particular week. If the latter is the case, of course, your offset estimates will be largely unaffected.

If, on the other hand, you are concerned about within-session reaction time differences (as opposed to week-to-week differences), this should again be taken care of, shouldn't it, by the constancy of these differences at both ends of the timing trial? However, if you mean reaction-time differences between clicking the watch on and stopping it, it seems to me that the averaging effect would, for the most part, take care of that. Your best guide to all of this is probably the magnitude of your standard deviations, and those you've been reporting (.02 - .03 sec.) are very small, indicating very good precision and small standard errors around your mean estimates.


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## Sabresoft

South Pender said:


> Frankly, I think that you have overemphasized the "variance in sampling precision" explanation. If there are reaction-time differences from week to week, these should manifest themselves at both ends of the timing procedure (at the beginning with the starting of the stopwatch on the reference clock and the end with stopping it on the minute marker of your watch).


I agree, and was thinking about this as I was writing my post, but at the same time I have noticed that I am not always reacting the same at both ends of the timing sequence. Probably more of a mental concentration problem I suspect. For the start click I aim to start on a particular major marker and if I miss I just let it run to the next marker. For the stop I am more focused (not wanting to waste a timing interval) and get the sense that my reaction is a little different. I can't quantify it, but I just get that feeling. And we are talking about 1/100 ths of seconds here.

Also I was looking at the extreme with both start and end reactions off in opposite directions. More realistically it is probably at one end of the cycle. But again enough of those and I may be cancelling out any effect. But I did do a bunch of same watch samples today doing six readings in a batch (start at one major marker, stop at the next) and in one instance I had a batch of six averaging 4.97 and the next batch averaging 5.03.

Certainly the larger magnitude of test-to-test variation would seem to be more likely from thermal variation than from my eye-hand reaction time issue. But some small amount could be from my reaction time aberrations. Long term I don't believe that it is causing any significant error, but the week-to-week variations are interesting, if not truly significant.

Another possible explanation for the week-to-week variations is the calibration of my timing source. I generally use the Skyhawk AT in the morning shortly after it has been synched (about 6 hours after). Theoretically even if the sync was perfect, the watch could have drifted by as much as 0.125 seconds (at 15 spm spec). In reality the syncs aren't always perfect, but then too the drift of the Skyhawk AT may be better than the 15 spm, with less impact on the 6 hour drift. To calibrate for this I do check the AT against the Emerald and Sequoia iPhone app and/or my NTP adjusted Mac clock and adjust my offsets against any difference that I find (I know I am adding more potential errors this way, but it's just easier to use two watches held side-by-side). I also have checked the Mac's clock against the E & S app, and find fairly good correspondence. In the end I don't think that these errors will have much impact in the final assessment. Each week's assessment is based on a projection to 365 days from that day's offset reading, early errors will distort projections, but at the 365 day point the impact of errors will be minimized.

In the end the 365 day SPY value will be the 365 day offset reading plus/minus any reading errors minus the initial offset plus/minus any reading errors.

Taking the CW C70 for example, let's say that the final offset difference is -7.5 seconds, and let's assume that I didn't correct my reference at one of the readings and so was off by a whole day's worth of Skyhawk AT drift of 0.5 seconds, and assume that all other errors are zero or cancel out over the year. That would translate into a potential range for my SPY value of between -7 and -8 seconds. I would be happy with either value. I'd be more concerned if the SPY was +14 or -21 instead of 7.

The overall thermal history will impact the results, but realistically the 16ºC and 24ºC are the extreme values for my storage scenario. The one day in about 15 that any one watch gets worn in my collection rotation might see slightly higher temperatures, but over the year an average temperature of 20ºC is not unrealistic and suggests an average of -0.02 spd versus the original test value of -0.01 spd at 23ºC.

The original COSC test value of 0.01 spd projects to -3.65 spy. If the average temperature history throughout the year is 20ºC, the projected spy is -7.3 seconds. This is not far off what my current projections are at between -7.57 and -7.88 spy based on this weeks offset readings. I can't do the same check for the Airwolf because the Breitling certificate does not include test data.


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## Hans Moleman

Sabresoft said:


> View attachment 596043


How a picture can say more than a thousand words.
That is a successful waste of a Saturday morning!


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## Catalin

Very interesting results - as you might remember back in the days when I was a lot more impulsive I was insisting that such non-random variations in the reaction time could take place :roll: (in which all measurements in a day are affected, but not in precisely the same way as all measurement one week later).

I believe that if we had the S/Y calculated on each of the SHORT intervals (instead of the S/Y from the cumulative time - which tend to show large errors at the start and much smaller errors after a long interval) plus some generic thermal info on each short interval we might even be able to estimate some part of the variance from those small measurement errors :think:


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## Sabresoft

Airwolf 271 Days, C70 180 Days, Precisionist, Skyhawk & UX 69 Days & Miros 21 Days

Latest table of results:









And the SPY estimate based on reading at date for Airwolf and C70:


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## artec

Thanks for this. 

Very interesting and positive results. The Precisionist just crawled in under the wire! How did you arrive at the figures in the final column, the SPY from the tend line?

I don't want to pick nits, but is the blue line on the graph, ending at 35 spy, actually the Citizen Skyhawk as opposed to a Seiko as shown in the legend under the graph? 

You have a much greater variety of watches than I have and you've tested them over much longer than I have (56 to90 days). I'm going to be posting my figures for my small group of all Japanese models shortly but I need to learn how to do graphs first!


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## Sabresoft

artec said:


> Thanks for this.
> 
> Very interesting and positive results. The Precisionist just crawled in under the wire! How did you arrive at the figures in the final column, the SPY from the tend line?
> 
> I don't want to pick nits, but is the blue line on the graph, ending at 35 spy, actually the Citizen Skyhawk as opposed to a Seiko as shown in the legend under the graph?
> 
> You have a much greater variety of watches than I have and you've tested them over much longer than I have (56 to90 days). I'm going to be posting my figures for my small group of all Japanese models shortly but I need to learn how to do graphs first!


I calculate the SPY values two ways.

The first is a projection based on seconds of offset measured at a given date, divided by the days in test at time of measurement times 365.

The second consists of tabulating the offset values versus number of days in test and then using the TREND function in Excel to predict the value at 365 days.

I don't have the data handy right now, but I could post it here.

The chart that I posted is my first test. Of the six watches in the test only the Airwolf and C70 are still "in test". Of the others the following happened:

Precisionist - watch got reset at the fall DST to ST change as minute hand has to be adjusted to change the hour. The Precisionist data in the table is for Test #2 started after DST.

Sinn UX - same story as the Precisionist.

Miros - the battery died (and new performance in Test #2 and Test #3 supports the theory that the accelerating bad values in Test #1 were due to progressive battery failure - in fact in the last 12 hours the watch actually gained 2 days!)

Seiko - sold to a co-worker.

I started Test #2 with the Precisionist, UX, Miros, and Skyhawk. After a few weeks I decided to adjust the Miros as it was showing fairly high (teens) SPY projections. So the Miros is all by itself in Test #3. So far the Miros looks to be doing quite well after adjustment, but it is early days right now and so I wouldn't want to put too much stock in the results just yet.

For graphs, Excel does the trick quite nicely. The basic plotting of data is fairly straight forward (tabulate your data, select it and choose "Insert Chart" command). Adding all the fancy features takes a little more time and some trial and error.


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## Sabresoft

artec said:


> Thanks for this.
> 
> Very interesting and positive results. The Precisionist just crawled in under the wire! How did you arrive at the figures in the final column, the SPY from the tend line?


Here's an explanation of how I derived my two different SPY estimates:


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## artec

Very kind of you to take the trouble to give us that explanation. I've been using the method you show as notes 1 and 2. Notes 3 and 4 apparently need familiarity with Excel which, alas, I'm short of. But since I want to post my own readings before too long, now that I have a test method that I'm satisfied with, I shall have to explore Excel to learn how to make graphs. You've done your bit, now I have to do my homework so that I can understand!

Thanks again.


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## Sabresoft

Just to mess things up a little I have decided that since we already know that the Skyhawk is headed for the mid thirties on SPY performance, I am going to wear it everyday for the next week. Up till now I have not been wearing it at all and so the testing has been based on storage conditions only. 

The watch was my daily (and only wear) for 10 years, and I seem to recall that it kept fairly good time, so I am curious to see if wearing it daily will impact results. Based on the data collected so far I would anticipate that if not worn over the next week to see a gain between 0.6 and 0.75 seconds. If the watch performs significantly better when worn I would expect to see a smaller gain over the week. So we'll see in a week's time.


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## Catalin

Sabresoft said:


> Just to mess things up a little I have decided that since we already know that the Skyhawk is headed for the mid thirties on SPY performance, I am going to wear it everyday for the next week. Up till now I have not been wearing it at all and so the testing has been based on storage conditions only.
> 
> The watch was my daily (and only wear) for 10 years, and I seem to recall that it kept fairly good time, so I am curious to see if wearing it daily will impact results. Based on the data collected so far I would anticipate that if not worn over the next week to see a gain between 0.6 and 0.75 seconds. If the watch performs significantly better when worn I would expect to see a smaller gain over the week. So we'll see in a week's time.


Yes, I always found that kind of comparative measuring - room vs (very) warm vs (very) cold - as very revealing on the true performance of the TC part (or the absence of it) :-!
(but keep in mind 2 weeks might provide better accuracy of the final result).


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## Sabresoft

Catalin said:


> Yes, I always found that kind of comparative measuring - room vs (very) warm vs (very) cold - as very revealing on the true performance of the TC part (or the absence of it) :-!
> (but keep in mind 2 weeks might provide better accuracy of the final result).


My other watches will be upset if I ignore them for that long. We'll see at the end of next week.


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## Catalin

Sabresoft said:


> My other watches will be upset if I ignore them for that long. We'll see at the end of next week.


A problem that I am familiar with :-d

I solved it by finding a (large) spot on my wireless router that is constantly over 30 degrees Celsius - so now I can keep there 3-4 watches ;-)


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## ronalddheld

That is a good solution that perhaps more of us can take advantage of.


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## dmmartindale

Sabresoft said:


> I agree, and was thinking about this as I was writing my post, but at the same time I have noticed that I am not always reacting the same at both ends of the timing sequence. Probably more of a mental concentration problem I suspect. For the start click I aim to start on a particular major marker and if I miss I just let it run to the next marker. For the stop I am more focused (not wanting to waste a timing interval) and get the sense that my reaction is a little different. I can't quantify it, but I just get that feeling. And we are talking about 1/100 ths of seconds here.


A thought: Are you measuring at the same time of day? If not, daily variations in rate that cancel out over the long term will leak into your data.

The temperature outside your house almost certainly increases and decreases in a 24-hour cycle. The inside temperature probably does not vary as much, but there's probably a 24-hour cycle there too (particularly if you set back the temperature at night during heating season). For any watch that is not perfectly temperature compensated, that means it will speed up and slow down each day too. If you measured the rate using a timing machine (say) every half hour and plotted all the measurements, you would see a 1 cycle-per-day ripple superimposed on the long-term trend.

Now, if you collect your data at exactly the same time each day (and that means the same time UTC, ignoring any changes in local time due to daylight savings time), the daily cycle cancels out, and you only see the long-term variation in timing, which is what you want. But if you *don't* measure at the same time, the "timing jitter" in your measurements will show up as jitter in the measured rate when in fact the rate is in fact following a perfectly predictable pattern.

- Dave


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## h2oflyer

I started using the router as a thermal storage pad and gave up. I feel it is introducing external control like radio synch. Wearing a watch 24/7, permanent storage at your ambient temperature, or a mix of both
is the watch's true temperature enviroment.

I just ran some quicky accuracy trials on my newly aquired Kinetic BFK, which is definately not HAQ. On wrist 24/7 for 9 days is +37 spy. A random mix of on/off wrist is average +65 spy. I could bring the +65 spy
down by storing the BFK on the router. But what's that prove?

Knowing the BFK is not HAQ and having some fun on these trials, I used my Skyhawk for everything....time signal, stop watch function, and circular slide rule. Now that's a tool watch.

Walter


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## Hans Moleman

dmmartindale said:


> A thought: Are you measuring at the same time of day? If not, daily variations in rate that cancel out over the long term will leak into your data.
> 
> The temperature outside your house almost certainly increases and decreases in a 24-hour cycle. The inside temperature probably does not vary as much, but there's probably a 24-hour cycle there too (particularly if you set back the temperature at night during heating season). For any watch that is not perfectly temperature compensated, that means it will speed up and slow down each day too. If you measured the rate using a timing machine (say) every half hour and plotted all the measurements, you would see a 1 cycle-per-day ripple superimposed on the long-term trend.
> 
> Now, if you collect your data at exactly the same time each day (and that means the same time UTC, ignoring any changes in local time due to daylight savings time), the daily cycle cancels out, and you only see the long-term variation in timing, which is what you want. But if you *don't* measure at the same time, the "timing jitter" in your measurements will show up as jitter in the measured rate when in fact the rate is in fact following a perfectly predictable pattern.
> 
> - Dave


Well spotted!

It will be a struggle to see that. 
My VHP loses 10 ms overnight when left out in a 13 ℃ spot.
Wearing it during the day makes it catch up again.

If an ordinary watch does 10 times as bad, 0.1 second might just be visible.


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## Sabresoft

dmmartindale said:


> A thought: Are you measuring at the same time of day? If not, daily variations in rate that cancel out over the long term will leak into your data.
> 
> The temperature outside your house almost certainly increases and decreases in a 24-hour cycle. The inside temperature probably does not vary as much, but there's probably a 24-hour cycle there too (particularly if you set back the temperature at night during heating season). For any watch that is not perfectly temperature compensated, that means it will speed up and slow down each day too. If you measured the rate using a timing machine (say) every half hour and plotted all the measurements, you would see a 1 cycle-per-day ripple superimposed on the long-term trend.
> 
> Now, if you collect your data at exactly the same time each day (and that means the same time UTC, ignoring any changes in local time due to daylight savings time), the daily cycle cancels out, and you only see the long-term variation in timing, which is what you want. But if you *don't* measure at the same time, the "timing jitter" in your measurements will show up as jitter in the measured rate when in fact the rate is in fact following a perfectly predictable pattern.
> 
> - Dave


I can see where testing time would be a factor. I usually do my readings either on Friday afternoon or evening, or Saturday morning.

I don't believe that the small week-to-week variations are of any sigificance in the general scheme of things and the overall trend will show through over the long term.


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## Sabresoft

Sabresoft said:


> Just to mess things up a little I have decided that since we already know that the Skyhawk is headed for the mid thirties on SPY performance, I am going to wear it everyday for the next week. Up till now I have not been wearing it at all and so the testing has been based on storage conditions only.
> 
> The watch was my daily (and only wear) for 10 years, and I seem to recall that it kept fairly good time, so I am curious to see if wearing it daily will impact results. Based on the data collected so far I would anticipate that if not worn over the next week to see a gain between 0.6 and 0.75 seconds. If the watch performs significantly better when worn I would expect to see a smaller gain over the week. So we'll see in a week's time.


I just couldn't wait for the full seven days to test my theory, so I had to check today after only 4 days, and to say the least I was astounded by my results. I was predicting a 7 day increase in the gain of something less than 0.6 seconds, hopefully measurable enough to be more than just within normal error. Based on 4 days I would have expected something less than 0.34 seconds based on past data.

What I actually measured was MINUS 0.63 seconds.

At first I thought to myself that this was great until I thought some more and realized that if this were representative of the performance on-wrist all the time, then my watch would actually be running slow, and could be as much as (-)58 SPY, actually worse than the off-wrist behaviour.

I'll run this mini-test till the weekend, but then my other watches want back into the action!


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## Catalin

Sabresoft said:


> I just couldn't wait for the full seven days to test my theory, so I had to check today after only 4 days, and to say the least I was astounded by my results. I was predicting a 7 day increase in the gain of something less than 0.6 seconds, hopefully measurable enough to be more than just within normal error. Based on 4 days I would have expected something less than 0.34 seconds based on past data.
> 
> What I actually measured was MINUS 0.63 seconds.
> 
> At first I thought to myself that this was great until I thought some more and realized that if this were representative of the performance on-wrist all the time, then my watch would actually be running slow, and could be as much as (-)58 SPY, actually worse than the off-wrist behaviour.
> 
> I'll run this mini-test till the weekend, but then my other watches want back into the action!


First of all - with an interval of just 4 days and the chrono method, errors of 5-10 s/y would be a clear possibility.

However the -58 spy is well beyond that :-d The result is not unexpected in any way - non-TC models very often show over 60 s/y of difference warm/room - actually I would say that today that is most often the norm, since just a minority of the quartz crystals seem to be "centered" around 25C as those should be :roll:


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## Sabresoft

Weekly Update

For days in test see table below:









The Skyhawk numbers were definitely affected by wearing the watch last week. The offset was 5.65 seconds versus 6.59 the week before, a negative shift of 0.94 seconds which would translate into approximately a -49 SPY versus the +35 SPY that the watch was showing until this mini-test. So a range of -50 to +50 SPY isn't inconceivable. That is -4.2 to +4.2 SPM, better than the expected -15 to +15 range for standard quartz, so for a non-TC movement this watch is still showing pretty good performance.

The chart below shows the SPY estimates for the four watches in the new test (Precisionist, Skyhawk, Miros and UX). There are two lines for the Miros, one going up to 48 days at which point I adjusted the watch and a new line currently only going to 28 days for the watch after adjustment (sort of Test 2a). You can also see the "dive" in the Skyhawk's SPY curve due to the daily wear test last week.









The next chart shows offset at days-in-test with a projection to 365 days using Excel's TREND function. There is a blip/correction in the Skyhawk line due to the daily wear test. If I continued to wear that watch all the time, the trendline would eventually turn down, as the as-worn data would outnumber the as-stored data.

The lower trendline for the Miros indicates that the adjustment did have an impact. Looks to be about roughly around 6 seconds, which is consistent with what I suspected - that I had made two successful hits out of three on the adjustment pads, each of which is supposed to shift the mechanism by approximately 3 seconds. If its performance stays consistent I may make another adjustment attempt in a few months to see if I can bring it down to 3 SPY. I don't want to aim for zero because I'd prefer slightly fast over slightly slow.









One thing is for sure, the Miros Chronograph is showing much better performance (be it at 13 SPY or 7) compared to its recently acquired non-chrono automatic sibling. Looks very similar minus the sub-dials. The automatic was clocking +30 SPD and is currently at my watch repair shop trying to get it slowed down a little.

Not sure what grade of Sellita SW200 was used for the watch, but it is not the COSC version.

Isochronism for Standard Grade is +/- 20 SPD, Special Grade is +/- 15 SPD, and Premium Grade is +/- 10 SPD.

Come DST change in March I may just terminate all the tests and start a new one with each watch set offset the opposite direction from the SPY value as follows:

Setting Offset = - SPY * 238 / 365 / 2

The 238 days is the days between DST start and end. The following table gives an idea of what values I would use (the actual values would be computed at the start of the new test, based on the results of the old tests). I would probably set the offset values to the nearest ½ or full second as trying to set a watch to two decimal places would be virtually impossible. The actual value for the test would be the as-accutually-offset reading after setting the watch.









If the watches stayed consistent over the 238 days the offset at that time should be close to the negative value of their initial offset, and at 119 days (July 8) they should all be close to zero offset. This should be interesting and would be a new twist on the offset data. At the same time I could also do the conventional test that I have been doing currently, just with a larger start offset.


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## Sabresoft

This Week's Update (January 27, 2012)

The data table:









As can be seen from the offset chart, the Skyhawk has resumed its former path since going back to its non-worn status:









Got to run right now because the B-I-L & S-I-L have just arrived for weekend visit.


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## Sabresoft

February 3, 2012 Update

Not a lot of words, but lots of charts this week:

SPY estimates for Airwolf and C70 Brooklands (updates). The old curves for Seiko, Sinn UX, Precisionist and Miros also showing (tests terminated in late October and early November).









The actual offset readings with Excel TREND projection to 365 days (Airwolf and C70 Brooklands only).









Weekly deviation in SPY estimate relative to the average of the SPY estimates (Airwolf and C70 Brooklands only). Days in test are from the start of the oldest test (Airwolf), the C70 Brooklands started later. Note how the two watches track each other fairly closely.









The variance from average SPY, but divided by days-in-test (and multiplied by 1000, so presented as milliseconds). This gives an indication of the sensitivity of the SPY estimates in the early stages of the test to sampling errors, gradually settling down as the tests progress. Don't know if the gently downward slope could be due to crystal aging.









The next two charts are for the new tests started in November.

The first is for the SPY estimates for the Precisionist, (non-AT) Skyhawk, Sinn UX and Miros. The Miros has two lines as the test was restarted again in December after adjusting the watch (two effective hits on the adjustment pads for an effective improvement of approximately 6 seconds per year). The blip in the Skyhawk curve is due to the watch being worn 18/7 one week. The old trend appears to be reasserting itself.









The second charts shows the actual offsets with Excel TREND projection to 365 days. The two Miros lines show that the post adjustment readings show approximately a 6 second improvement in projected SPY value.









The summary table follows:









General conclusions from the data so far:

1. Three of the TC watches show reasonable behaviour (in the 5 to 10 SPY range).
2. The Sinn is between 10 and 15 SPY, but would need to go back to Germany for adjustment.
3. The Precisionist is within COSC (barely) when not worn. I may try a whole week (18-7) wearing only the Precisionist to see if the performance changes (improves hopefully).
4. The non-TC watches (Seiko in the first test, and the Skyhawk in the second) perform better than +/- 15 SPM, falling just outside the COSC limits on SPY (aprox 2.5 SPM).

All-in-all not a bad set of watches. Interestingly one watch, the Independent ITA21-5141, that has not been tested because it was up for sale (I decided today as there has been no interest that I would keep it) is showing an approximate SPY just outside COSC.

Next test might just be my automatics where we will track the HPY performance (I have one that is in for servicing right now that was tracking to over 3 hours per year!).


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## Catalin

Sabresoft said:


> February 3, 2012 Update
> ...
> 2. The Sinn is between 10 and 15 SPY, but would need to go back to Germany for adjustment.
> ...


I don't think it is worth sending the watch back just for that (especially since it is not clear if that would be covered by warranty) - ideally you should track it close to the moment when the battery dies and just have things adjusted at that point (especially since aging will become slightly more stabilized by that time).


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## Sabresoft

Catalin said:


> I don't think it is worth sending the watch back just for that (especially since it is not clear if that would be covered by warranty) - ideally you should track it close to the moment when the battery dies and just have things adjusted at that point (especially since aging will become slightly more stabilized by that time).


I was kind of implying that as there would be a cost/shipping risk for a minor adjustment.

I was cruising the Sinn site this morning and checked on their UX page and they only commit to +/- 20 SPY anyway, so it's doubtful that they'd do anything at 14, even if the caliber is more capable.

As I have to reset the watch at DST/ST changes anyway it will only be about 7-8 max offset, and if I use the negative half offset concept at setting time, it would only be off by about 4 seconds at most. I can live with that.


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## Sabresoft

*February 11, 2012 Update*

The latest table is presented below:









This last week I tried the 18/7 wear pattern on the Precisionist to see if this would change the SPY projection. The chart below shows that there wasn't a significant difference. I had hoped that SPY would improve, but actually it got worse, although no worse than a couple of other times while the watch wasn't being worn.









Compared with the Skyhawk which showed a significant difference in projected SPY for the 18/7 wear week, the Precisionist really didn't show much reaction to the change in wear pattern. Now, thinking back, there was one event during the week that may have distorted the data, and that was last Sunday when I cleared the driveway of a light snow covering from a few days earlier, with the watch fully exposed to about -1ºC/31.4ºF (probably 20 minutes, but I wasn't wearing a winter jacket, just a heavy fleece vest).









It would probably require a few more weeks of testing the Precisionist at an 18/7 wear pattern to draw any firm conclusions, but it would appear that the Precisionist is less temperature sensitive than a normal 32 kHz quartz, and that my 25 to 26 SPY estimate range is just due to the fact that the watch is not performing at the claimed +/-10 SPY quoted by Bulova, which is no surprise to many here on the forum.


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## Sabresoft

*Accuracy Report February 17, 2012*

Just an updated chart this week.


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## Sabresoft

February 24, 2012

Table updated this week:
- The Miros, Airwolf and C70 are projecting to less than 10 SPY
- The Sinn UX less than 15 SPY, and 
- The Precisionist is at around COSC limits
- The Non-AT Skyhawk is performing at better than spec, but is still at around 2.5 SPM


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## Sabresoft

*Accuracy Report March 2, 2012*

Focusing mainly on the Airwolf and C70 this week.

The SPY estimate chart:









The current offset chart with Excel TRENDLINE to 365 days:









Looking at the Variance from Average SPY Projection (possibly showing aging effect?):









Looking at Variance from Average (SPY Estimate) Divided by Days-in-Test measured in Milliseconds:









Finally showing how the SPY Estimate (Chart 1) and Actual Offset with TRENDLINE to 365 Days (Chart 2) methods of SPY estimate are converging to the same value:









The Weekly Data Table:


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## Sabresoft

Well this is the end of the road for these two tests. I have decided to reset all my watches with an offset based on the past SPY experience, such that approximately half of the expected offset over this year's DST interval (238 days) will be applied negatively as an initial offset on Sunday when adjusting the watches for DST.

I'll get to that later. For now, here are the final charts:

*Breitling Airwolf and Christopher Ward C70 Brooklands
*
SPY Estimates from weekly offset readings, clearly both are showing an estimate around -8 SPY









Weekly Offset Chart, with Excel TRENDLINE to 365 Days:









Chart showing variance from average SPY projection.









Variance from average divided by number of days in test, measured in milliseconds









I had hoped to see the test out to 365 days for the Airwolf to see the convergence of the two lines, but it is quite clear from the chart at 327 days that this is going to happen. Note 3 should actually say from 327 to 365 days.









The second test is shown below, with the SPY estimates from weekly offset readings shown first:









The weekly offset readings with Excel TRENDLINE projection to 365 days.









Finally I decided to chart the two Sinn UX sets of test data, using the offsets and TRENDLINES to 365 days. They are close, but I wonder if the slightly higher curve for Test 2 could be a sign of crystal aging?









Finally the results table, with a new column added showing the initial offset planned for Sunday when resetting the watches for DST. I don't think that I am going to bother with the Skyhawk, and maybe not even with the Precisionist, just the TC watches. I'll report the actual initial offsets, probably in a new thread, and will predict offsets at certain future dates, and will revisit them on or around those dates to see how good the projections actually were.


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## Sabresoft

I thought that I had posted an update in July. Guess I did the legwork for the update but never got around to uploading. Anyway here is my update for September. Again this is based on setting the watches at March DST date to negative half the previous test offset, adjusted for the DST period versus a full 365 days. The chart shows the predicted and actual offsets today.


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## Fer Guzman

this is intense tracking, I am going to start doing it for my ctq57. I have only had it weeks and I it was purchased a couple of weeks ago, so far the first week it was running less than a second slower, like half a second. After I started wearing it, and I wear it at least 4 days a week for about 8-10 hours every day, it is now almost to the dot to time.is and almost identical to all my atomic g-shocks. It definitely almost exact after having worn it so much. I assumed it would be off by 10 seconds since the previous owner said it was purchased 2 yrs ago, so I am very pleased about its accuracy.


Great Posts!


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## Sabresoft

I have created charts comparing the 2011 and 2012 tests predicting SPY performance:

*Breitling Airwolf Raven:*









*Bulova Precisionist Claremont:
*








*Christopher Ward C70 Brooklands:*









*Maurice Lacroix Miros Diver Chronograph:*









*Sinn UX:*









As I don't control for temperature, and have more watches so that wearing patterns have changed, with longer gaps between wearings for any given watch, I cannot really properly assess the differences between the 2011 and 2012 tests. The smoother 2012 curves are due to less frequent readings, so there is less of the sawtooth up and down that occurred with the more frequent readings in 2011.

Two possible explanations for the differences in the two tests are:

1. This summer was warmer than last year;
2. We might be seeing some crystal aging effects.

Clear conclusions though are that:

1. The Airwolf and C70 provide excellent accuracy (less than 10 SPY)
2. The Miros & UX provide satisfactory accuracy (10-15 SPY) - The Miros could probably do with another dose of adjustment, the UX while not user adjustable due to the oil fill, does need to be reset at DST/Non-DST changes, so actual useful accuracy is within 10 seconds between DST changes.
3. The Precisionist continues to get worse, but to be fair gets little wrist time, less because of its inaccuracy and more because I prefer watches with more complications, so days when I think that I might wear it, I end up changing my mind in favour of something else. The new Chrono version of the Precisionist may be a future candidate.


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## Eeeb

Great data! Thanks


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## ronalddheld

Keep up the good data collection!


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## Sabresoft

*Update Saturday October 27, 2012*

Latest offset chart:









Looking at the individual charts, starting with the best two watches, the Breitling Airwolf Raven and Christopher Ward C70 Brooklands:















SPY performance definitely less than 10 SPY and closer to 5 SPY.

Next is the Maurice Lacroix Miros, which is a little over 10 SPY, and could probably do with another hit on the adjustment terminals:









A little disappointed with the Sinn UX, but it would have to go back to Sinn for adjustment due to the oil fill, and I believe that as they claim around 15 SPY, they won't adjust a watch that is close to spec:









Because of the size of my collection, and the fact that I wear most of my watches I'd say that the above watches get worn one or two days out of any 14 day period, so most of their time is spent off-wrist, so the results are pretty good.

The Bulova Precisionist Claremont performance is less satisfactory, but then admittedly it gets little wrist time (as I prefer watches with more complications), and the performance seems to be getting worse over time as some have discovered:









As an interesting exercise I have also charted my entire "Accuracy Gang" watches, showing expected out-of-the drawer errors based on the practical sync/reset periods listed in the table. This isn't really a fair comparison because 3 TC watches are based on an annual error, and one TC and the Precisionist are based on a 283 day error (due to DST changes). The 3 TC watches would have even better performance if based on 283 days. The RC watches are basically accurate pretty much all the time based on my general at home sync performance.









Basically all but the Precisionist (9 watches) can be relied upon to be within about 10 seconds of correct time, and 7 watches would be within 5 seconds.


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## Sabresoft

*Sunday November 4, 2012 - DST Time Change*

Well the current test has come to an end for two of the watches, the Precisionist and the Sinn. The table below shows the final results. As can be seen none of the watches was at the predicted offset. Some were better and some worse.









The Miros definitely looks like a dose of adjustment is in order. The Precisionist is definitely not performing at anywhere close to the advertised 10 SPY. I seem to recall reading somewhere (maybe here in this forum) that off-spec Precisionists could be sent back for adjustment. Might be worth a try.

The 2011 vs 2012 test comparison charts follow:









































I will continue the test with the three remaining watches until I hit 365 days and the start a new test in 2013. I will see if I can get the Precisionist adjusted, and if not, or if performance doesn't improve I might just sell it as my collection is getting larger than I had planned, and so all my under performing watches may find themselves on the chopping block.


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## Sabresoft

*Day 256 in 2012 Test

*Three watches remain in the test, the Precisionist and Sinn UX having dropped out at DST change on October 4, due to being reset. No new test has been started yet for these two.









And the SPY prediction curves:


----------



## Sabresoft

*Day 273 in 2012 Test*


----------



## webvan

Thanks for the update, nice accuracy and...nice graphs, what software do you use?


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## Sabresoft

webvan said:


> Thanks for the update, nice accuracy and...nice graphs, what software do you use?


Excel (2011 on the Mac), and then I use GraphicConverter to make JPEGs from Copy As Picture clip from Excel.


----------



## Sabresoft

*Day 291 in 2012 Test*


----------



## Sabresoft

*First update of the new year:*

































This chart compares the three watches:


----------



## Sabresoft

Taking a look at my results in terms of actual offset from "Real" time (I use parentheses because my definition of real time may not be totally accurate, but is close enough, say within 0.1 seconds).

The following chart shows all 5 watches that were in the initial 2012 test, all of which were set to an offset (on the switch to DST) that should have been 50% of the expected cumulative offset at the end of DST. This offset was based on the 2011 SPY tests. I predicted that at the mid point between DST-on and DST-off all the watches should be close to zero. As can be seen the crossing points are all over the map:









Clearly the Precisionist is not in the same league as the TC watches, despite Bulova's claim of 10 SPY. But the 4 TC watches were no worse than 6 seconds off "real" time at any point during the test, and the best two, the Airwolf and Brooklands were no more than 3 seconds.

The next chart eliminates the Precisionist "imposter" and more clearly shows the results for the other 4.


----------



## Hans Moleman

Sabresoft said:


> View attachment 958547


For the lazy amongst us: Me for instance.
Very easy to read that!
|>


----------



## xxmikexx

Hans Moleman said:


> For the lazy amongst us: Me for instance.
> Very easy to read that!
> |>


Indeed. Kindly tell us, Sabresoft ... Why do all three graphs feature a similar dip-and-recovery beginning around day 275?


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## Sabresoft

xxmikexx said:


> Indeed. Kindly tell us, Sabresoft ... Why do all three graphs feature a similar dip-and-recovery beginning around day 275?


I had noticed that yesterday but didn't have the time to check it out further. Today I looked at the data for Day 273, and eliminated it, but there was still a noticeable wrinkle in the curve. I then put that data back and looked at the data for Day 291. It is possible that the data collection for that date was corrupted by a procedural error.

I use my Citizen Skyhawk AT as the timing device to check the other watches. I start the stopwatch on the Skyhawk when the second hand passes a marker on the subject watch and click off the stopwatch when the Skyhawk second hand passes the marker five seconds later and the take the reading. For example if the second hand passes the 15 second marker on the Breitling I start the stopwatch and then stop it when the Skyhawk passes the 20 second marker. If the two were exactly matched I'd get a reading of 5.00. If I get a reading greater than 5 the Breitling is faster, and if less than 5 it is slower. The offset reading is then the stopwatch reading minus 5. Projected SPY is then calculated as (today's offset minus initial offset measured at start of test) divided by (days in test) times (365).

Before starting the test I calibrate the Skyhawk against basically NTP servers. Theoretically the Skyhawk could be off by as much as 0.15 seconds (assuming a test time of 9:00 AM and a RC sync time of 2:00 AM). My usual measured offset is plus 0.03 to plus 0.06 seconds; so instead of subtracting 5 seconds from the stopwatch reading it'll be 5.03 or 5.06. The Skyhawk offset was 0.34 seconds on Day 291. It may be that it hadn't synced in a few days (quite possible if I leave it in stopwatch mode as RC does not work in that mode, or if I left it in a part of the house where no RC signal comes in). The other possibility is that my NTP calibration was faulty. Being lazy I tend to just use the menubar clock on my Mac, which is set by NTP servers on a regular basis, but maybe on that day was off for some reason (usually when I check it against a freshly synced Skyhawk it is bang on). Now the clock only shows seconds, not tenths or hundredths, but just as I use the second hand hitting the marker on a watch, I use the clickover of the second as my trigger point.

I just checked the clock against Emerald & Sequoia on my iPhone and get the clock being about 0.03 seconds fast right now.

All sorts of opportunities for error in my procedure, but generally I get acceptable results. Obviously Day 291 wasn't one of them. Eliminating that data yields the following curves:









When I was tracking almost weekly (my 2011 tests) the curves had many small wrinkles in them, which is a testament to my procedural quality, but overall a trend was discernible from the data. Of course the effect of offset errors are significant in the early stages of a test. For example with a SPY projection say one month into the test a 0.06 second error translates into 0.73 seconds in the projected SPY value. On day 365 the same error is only 0.06 seconds error in the SPY value.


----------



## xxmikexx

Sabresoft said:


> I had noticed that yesterday but didn't have the time to check it out further. Today I looked at the data for Day 273, and eliminated it, but there was still a noticeable wrinkle in the curve. I then put that data back and looked at the data for Day 291. It is possible that the data collection for that date was corrupted by a procedural error.
> 
> I use my Citizen Skyhawk AT as the timing device to check the other watches. I start the stopwatch on the Skyhawk when the second hand passes a marker on the subject watch and click off the stopwatch when the Skyhawk second hand passes the marker five seconds later and the take the reading. For example if the second hand passes the 15 second marker on the Breitling I start the stopwatch and then stop it when the Skyhawk passes the 20 second marker. If the two were exactly matched I'd get a reading of 5.00. If I get a reading greater than 5 the Breitling is faster, and if less than 5 it is slower. The offset reading is then the stopwatch reading minus 5. Projected SPY is then calculated as (today's offset minus initial offset measured at start of test) divided by (days in test) times (365).
> 
> Before starting the test I calibrate the Skyhawk against basically NTP servers. Theoretically the Skyhawk could be off by as much as 0.15 seconds (assuming a test time of 9:00 AM and a RC sync time of 2:00 AM). My usual measured offset is plus 0.03 to plus 0.06 seconds; so instead of subtracting 5 seconds from the stopwatch reading it'll be 5.03 or 5.06. The Skyhawk offset was 0.34 seconds on Day 291. It may be that it hadn't synced in a few days (quite possible if I leave it in stopwatch mode as RC does not work in that mode, or if I left it in a part of the house where no RC signal comes in). The other possibility is that my NTP calibration was faulty. Being lazy I tend to just use the menubar clock on my Mac, which is set by NTP servers on a regular basis, but maybe on that day was off for some reason (usually when I check it against a freshly synced Skyhawk it is bang on). Now the clock only shows seconds, not tenths or hundredths, but just as I use the second hand hitting the marker on a watch, I use the clickover of the second as my trigger point.
> 
> I just checked the clock against Emerald & Sequoia on my iPhone and get the clock being about 0.03 seconds fast right now.
> 
> All sorts of opportunities for error in my procedure, but generally I get acceptable results. Obviously Day 291 wasn't one of them. Eliminating that data yields the following curves:
> 
> View attachment 959762
> 
> 
> When I was tracking almost weekly (my 2011 tests) the curves had many small wrinkles in them, which is a testament to my procedural quality, but overall a trend was discernible from the data. Of course the effect of offset errors are significant in the early stages of a test. For example with a SPY projection say one month into the test a 0.06 second error translates into 0.73 seconds in the projected SPY value. On day 365 the same error is only 0.06 seconds error in the SPY value.


Thank you, that all makes perfect sense.

Do you care to comment on the relative performance of the three watches? That is, do you expect that other owners of the same three watch brands/models would get comparable results? Or might the graph brand/model labels be interchanged, so to speak?


----------



## Sabresoft

xxmikexx said:


> Thank you, that all makes perfect sense.
> 
> Do you care to comment on the relative performance of the three watches? That is, do you expect that other owners of the same three watch brands/models would get comparable results? Or might the graph brand/model labels be interchanged, so to speak?


I'm sure that every watch is different to some degree. I'm seeing some consistent behavior in these watches from year to year. That said the Brooklands and the Miros use exactly the same caliber, so clearly there are differences. I did do an adjustment on the Miros, because before it was running at about 15 SPY.

Certainly I am happy with these three, and even the UX which is running at around 15 SPY. To adjust the UX it would have to go back to Sinn in Germany, but they only guarantee to +/- 15 SPY, so would not adjust my watch anyway, even though theoretically it is adjustable. But then as the watch has to be reset at DST/non-DST changes it is at worst out by about 8 seconds.


----------



## xxmikexx

Sabresoft said:


> I'm seeing some consistent behavior in these watches from year to year.


If these were mechanical watches, one could hope to learn to be able to regulate them to one's personal wearing style till the all gave comparable (and excellent) results. However, it seems to me that the Achilles heel of quartz watch temperature compensation is that what you gain in on-the-wrist-versus-off-the-wrist stability you may (may) lose in ability to regulate.

Your reaction?


----------



## everose

xxmikexx said:


> However, it seems to me that the Achilles heel of quartz watch temperature compensation is that what you gain in on-the-wrist-versus-off-the-wrist stability you may (may) lose in ability to regulate.


I am not sure if i understand your point correctly,....Are you suggesting that TC mvts cannot be adjusted ?

ETA TC's can be adjusted and many mvts from the past also had this ability via differing methods. Some around here have successfully adjusted their 9F's too. An adjustment feature is not dependant upon TC or lack thereof.

Check out the *"Thermocompensation: Methods and Movements"* sticky for much more details of which mvts can/cannot be adjusted.

For some around this forum an adjustment ability is an important feature,.....for others,....not so much.


----------



## xxmikexx

everose said:


> I am not sure if i understand your point correctly,....Are you suggesting that TC mvts cannot be adjusted ?
> 
> ETA TC's can be adjusted and many mvts from the past also had this ability via differing methods. Some around here have successfully adjusted their 9F's too. An adjustment feature is not dependant upon TC or lack thereof.
> 
> Check out the *"Thermocompensation: Methods and Movements"* sticky for much more details of which mvts can/cannot be adjusted.
> 
> For some around this forum an adjustment ability is an important feature,.....for others,....not so much.


I'm really saying that the ideal would be a temperature-compensated quartz that could be easily regulated by my son and son-in-law to compensate for changes in wearing patterns, without their having to open the case, just as a mechanical easily can, by the way you store it when it's off the wrist.

As matters stand, if I talk them into HAQs they will have to live with whatever the (temperature compensated) accuracy happens to be, though in practice they don't give a rodent's rear about accuracy, see the How Accurate Is Your HAQ? thread.

What would be acceptable to me is a different matter so I will read the stickied thread when I get a round tuit. However, the point is almost moot for me personally since I expect to be holding my Timex to within 0.1 spy throughout the year without taking any extraordinary measures.

xxxxxxxxxxxxxxxxxxxx

FYI, as I've discussed elsewhere in this forum I'm effectively temperature-compensating my Timex myself by the way I wear it. It is on my wrist basically 23.5x7 and under these conditions it does -5 spy, though I've been keeping it to within 0.1 seconds absolute. If I want to lose a tenth of a second I put it in the refrigerator for 30-60 minutes. If I want to gain a tenth of a second I put it on the floor by my desk for about a day.

True temperature compensation built into the watch would greatly stretch out the time intervals required to gain or lose 0.1 seconds through this kind of trick. You might say "Well, go with a quartz movement that you can regulate". My immediate reaction is that I really don't want the case opened -- not by me, not by my watchmaker -- unless it's absolutely necessary, such as for a battery change.


----------



## McAllan

xxmikexx said:


> FYI, as I've discussed elsewhere in this forum I'm effectively temperature-compensating my Timex myself by the way I wear it. It is on my wrist basically 23.5x7 and under these conditions it does -5 spy, though I've been keeping it to within 0.1 seconds absolute. If I want to lose a tenth of a second I put it in the refrigerator for 30-60 minutes. If I want to gain a tenth of a second I put it on the floor by my desk for about a day.
> 
> True temperature compensation built into the watch would greatly stretch out the time intervals required to gain or lose 0.1 seconds through this kind of trick. You might say "Well, go with a quartz movement that you can regulate". My immediate reaction is that I really don't want the case opened -- not by me, not by my watchmaker -- unless it's absolutely necessary, such as for a battery change.


So you're happy about your Timex and want to convince us? Congrats.
So despite you're able to keep that sample on track with those tricks does not make it HAQ. It however has an adjustment and temperature performance to allow those tricks to work. Another Timex even of the same brand bought at the same time may not unless you go to extremes.

I agree though that it would be nice if manufacturers included a true user adjustable rate. Or wait many are by buttons/trimmer in the battery compartment. But I know what you mean - without opening it - and easy. Should be no bigger problem implementing on a digital (or ana/digi) watch. But then manufacturers face a big problem. If one user gets great performance with an adjustment of 0 then another user who might have to set adjustment for -100 (whatever minus 100 means) then that user feels he has a bad watch since is need that "big" correction. They could counteract that by hiding the true value for the customer and let like 2813 be equal to zero (but don't tell anyone what the true 0 looks like). So if your watch 20 spy fast then just subtract 20 from whatever number your calibration shows and set it there. Or perhaps performance per month. Whichever they find the most user friendly.

I only know one such timekeeper with that ability. Unfortunately not a watch. This kit clock (bought cheaper from local supplier):







(In a home made solid oak bar with dark red plexiglass front and stainless steel hardware)
Using not 4.19 MHz but 4.00 MHz AT cut crystal. 4.00 MHz because using a µC one is not limited to a nice binary round number. No trimmer - both load capacitors are fixed NP0 for best temperature performance. Well, as good as the computer grade crystal is - it's not exactly a marine chronometer grade crystal but none the less _much_ better than an uncompensated 32 KHz tuning fork. Adjustment is made digitally and adjusted via a menu. It corrects 1000 times a day. I have thought of replacing the crystal with a better one than that included in the kit.
It's performance in reality: True HAQ less than a handful of sec/year wrong with careful adjustment. Those interested can read the assembly manual for the technical info and info about adjustment.


----------



## ronalddheld

Is anyone else going to buy the kit and check out the performance?


----------



## xxmikexx

ronalddheld said:


> Is anyone else going to buy the kit and check out the performance?


I might request one for Christmas. If I get really interested I might negotiate with my wife to get one immediately.

The user manual says that the PIC source code is available but the manual's link to the source code is broken. I used to know the PIC and would be comfortable trying to change the clock code to do an automatic variable quarterly adjustment in order to better accomodate the roughly four degree summer/winter temperature difference in our condo unit.


----------



## xxmikexx

McAllan said:


> So you're happy about your Timex and want to convince us? Congrats.
> So despite you're able to keep that sample on track with those tricks does not make it HAQ.


Right. This forum would be more appropriately named "High Price Quartz, Accuracy A Secondary Consideration". Then I could reasonably call my highly accurate quartz a Highly Accurate Quartz.

It all depends on what you mean by accuracy and what you mean by tricks. Off the wrist my Timex gains 50 seconds per year over the course of a year, or on average a little more than 4 spm, with no attention whatsoever.

With the "trick" of wearing at all times except when showering/shaving or operating jackhammers, it loses 5 spy. The only "trick" is holding it to 0.1 spy.

If I bought another watch just like it could I expect a similar result? No. If I bought five like it could I expect one to perform as well? Maybe. If I bought ten like it could I expect a winner? Probably. A hundred? Almost certainly.

So what would be variable here would be the price (how many watches I had to discard at $65 each) till I got to a winner, not the accuracy of the winner.

Might a randomly chosen HAQ be more accurate than my -5 spy on-the-wrist result? Yes, but I wouldn't be able to hold it to 0.1 spy. That's the "problem" with temperature compensation -- you lose the ability to regulate it in reasonable time unless you go with an adjustable movement for which you're willing to open the case, which I am not.

xxxxxxxxxxxxxxxxxxxx

I'm not trying to tell people what they should want. Instead my message is, Every time you hear about a "fluke" super accurate El Cheapo quartz watch, the brand turns out to be Timex.


----------



## xxmikexx

xxmikexx said:


> I might request one for Christmas. If I get really interested I might negotiate with my wife to get one immediately.
> 
> The user manual says that the PIC source code is available but the manual's link to the source code is broken. I used to know the PIC and would be comfortable trying to change the clock code to do an automatic variable quarterly adjustment in order to better accomodate the roughly four degree summer/winter temperature difference in our condo unit.


Never mind -- too much soldering for my taste. But if I could take a look at the source code I might be willing to buy a PIC developer kit-with-prom-burner (or whatever) to make the changes I was talking about for somebody else to try. Who knows -- might be a hobbyist product lurking in the resulting software.


----------



## xxmikexx

xxmikexx said:


> Right. This forum would be more appropriately named "High Price Quartz, Accuracy A Secondary Consideration". Then I could reasonably call my highly accurate quartz a Highly Accurate Quartz.
> 
> It all depends on what you mean by accuracy and what you mean by tricks. Off the wrist my Timex gains 50 seconds per year over the course of a year, or on average a little more than 4 spm, with no attention whatsoever.
> 
> With the "trick" of wearing at all times except when showering/shaving or operating jackhammers, it loses 5 spy. The only "trick" is holding it to 0.1 spy.
> 
> If I bought another watch just like it could I expect a similar result? No. If I bought five like it could I expect one to perform as well? Maybe. If I bought ten like it could I expect a winner? Probably. A hundred? Almost certainly.
> 
> So what would be variable here would be the price (how many watches I had to discard at $65 each) till I got to a winner, not the accuracy of the winner.
> 
> Might a randomly chosen HAQ be more accurate than my -5 spy on-the-wrist result? Yes, but I wouldn't be able to hold it to 0.1 spy. That's the "problem" with temperature compensation -- you lose the ability to regulate it in reasonable time unless you go with an adjustable movement for which you're willing to open the case, which I am not.
> 
> xxxxxxxxxxxxxxxxxxxx
> 
> I'm not trying to tell people what they should want. Instead my message is, Every time you hear about a "fluke" super accurate El Cheapo quartz watch, the brand turns out to be Timex.


In the minicomputer business of the 1970s we used to say "You can build quality in, or you can test it in." The same is true with respect to quartz watches.

What would your reaction regarding product prestige be if it turned out that the reason your TC HAQ costs so much is that the manufacturer discards 28 of 30 crystals on the twin crystal production lines to get to the TC crystal pair that meets their spec?

Would you say that their cherry picking to 20 spy is prestigious but my cherry picking to 5 spy is not?


----------



## McAllan

xxmikexx said:


> Never mind -- too much soldering for my taste. But if I could take a look at the source code I might be willing to buy a PIC developer kit-with-prom-burner (or whatever) to make the changes I was talking about for somebody else to try. Who knows -- might be a hobbyist product lurking in the resulting software.


Ahh found the source code. Google's link is to the old part of the website. The manufacturer of the kit apparently has changed the website and Google points to some old pages left in limbo on the server for some odd reason. Anyway link is:
Kitsrus.com

Really the kit is dead easy to assemble if you've just got the slightest experience with a soldering iron. Probably I assembled in it 30 minutes or less. What was the challenge however was finding a suitable enclosure. It's a stupid size not really fit to any ready made electronic enclosures I could find just needing a few holes, a plexiglass window etc.
So I had to make my own. First I thought of an enclosure like the one illustrated on the magazines website but thought it was a bit too home made looking (yeah also make it of pine wood is cheap). Since I really don't have the facilities home to make such an enclosure and the time needed for it to glue I thought of something else. A family member has a manual CNC (or what to call it) perfectly suitable to hollow out a solid oak bar. Granted it took some time just to roughly make the shape of the enclosure then sanding and drilling needed holes afterwards (remember breathing holes on bottom and back where voltage regulator is as wood is quite insulating). Last but not least give it linseed oil multiple times to really close the pores in the wood. I did not want a lacquered finish. Since I used pure linseed oil without drying additives (because pure IMHO gives superior end result) it had to dry many times for long periods. Total time to make the encloure? I don't know. Probably in the order of 6 active hours but the whole process took weeks to finish. The result however is outstanding. Actually quite happy I couldn't find a suitable enclosure because it would then look like a typical DIY project of the 80s. Now it looks like something high end (hey it is high end! b-)) bought in a very expensive luxury store. You can really feel the wood (and the weight of it) and quality through out. Not plastic like the the "wooden" block clocks that originally inspired me and looks like what it is - cheap plastic (most of them at least) when you see them in real.



xxmikexx said:


> Right. This forum would be more appropriately named "High Price Quartz, Accuracy A Secondary Consideration". Then I could reasonably call my highly accurate quartz a Highly Accurate Quartz.
> 
> It all depends on what you mean by accuracy and what you mean by tricks. Off the wrist my Timex gains 50 seconds per year over the course of a year, or on average a little more than 4 spm, with no attention whatsoever.
> 
> With the "trick" of wearing at all times except when showering/shaving or operating jackhammers, it loses 5 spy. The only "trick" is holding it to 0.1 spy.
> 
> If I bought another watch just like it could I expect a similar result? No. If I bought five like it could I expect one to perform as well? Maybe. If I bought ten like it could I expect a winner? Probably. A hundred? Almost certainly.
> 
> So what would be variable here would be the price (how many watches I had to discard at $65 each) till I got to a winner, not the accuracy of the winner.
> 
> Might a randomly chosen HAQ be more accurate than my -5 spy on-the-wrist result? Yes, but I wouldn't be able to hold it to 0.1 spy. That's the "problem" with temperature compensation -- you lose the ability to regulate it in reasonable time unless you go with an adjustable movement for which you're willing to open the case, which I am not.
> 
> xxxxxxxxxxxxxxxxxxxx
> 
> I'm not trying to tell people what they should want. Instead my message is, Every time you hear about a "fluke" super accurate El Cheapo quartz watch, the brand turns out to be Timex.


That's the difference between HAQ and non HAQ. HAQ you can expect to have a certain amount of accuracy without your attempts to influence it one way or the other. Non HAQ you can not. Using the same logic you can claim some random chosen mechanical is more accurate then a Citizen Chronomaster because you lay it differently on the night table depending on whether it's fast or slow_ compared to some reliable time source_.
But what if you do not have access to a reliable time source though out the year? What can you expect to be closest to reality when the year of autonomy has passed? Your Timex or your Chronomaster?

Timex. Here Timex is of course known when you mention the name but it's rather uncommon. Cheap watches here is Casio (even though Casio also make some quite expensive models too - whether they're HAQ remains a question but I doubt it else they've most likely been up in this HAQ forum).


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## ronalddheld

We Are interested in accuracy first. Cost is not the primary driver in this forum.


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## xxmikexx

McAllan said:


> ... fast or slow_ compared to some reliable time source_. But what if you do not have access to a reliable time source though out the year?


We've been over this before ... timeanddate.com is accurate to less than 0.1 seconds according to the NIST voice clock, and it runs perfectly on the combination of Firefox and Windows XP/7, at least, and a forum member said that he checked it from his Mac and found it to be within a couple of milliseconds of NTP time. It's a good guess that it's both available to everyone throughout the year and will be accurate essentially all the time. Again, I've seen it drop ticks but I've never seen it lag or lead them.

xxxxxxxxxxxxxxxxxxxx

I hear you about the soldering. My skills are negligible but if there is little risk of overheating a component I might be willing to give it a try. However, I'm going to have to check on the price for a PIC develope kit with Eprom burner.

Regarding the software, I downloaded it (thank you) and skimmed it. I will have to get a PIC cpu manual to see how much RAM there is (was it 128 bytes?) versus how much is used by the Kitsrus code, but if we make the working assumption that there's plenty of RAM (whatever that means in practice) then I think the quarterly adjustment logic would not be too difficult.

The real issue would be deciding how to communicate with the PIC through the front panel -- we would probably have to go to a button push sequence protocol of some kind.

... Which reminds me ...

I was speed reading but I didn't see any software button debounce logic, only a single read of a status register that gives the state of the buttons. (Or so it appeared when I was skimming.) Can you confirm that the hardware is handling debounce?

xxxxxxxxxxxxxxxxxxxx

I would probably build it without a cabinet. If gentle air currents turned out to affect temperature stability I probably would then create an ugly clock housing out of cardboard.


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## xxmikexx

Here is a nice PIC development system. Unfortunately, before even considering the clock kit, with bells, whistles and shipping the development system is probably $300 all by itself, simply out of the question for me because I won't ask my wife to agree to a $400 hobby project.

(If she were to agree to that kind of sum I would rather spend that and a little more on an elabore grade ETA 2824-2 as cased up by Wilson Watch Works in the USA. This is off-topic for the HAQ forum but it would be another regulate-it-myself project, this time with me being willing to open the case to get at the regulator screw. I would give the result to my oldest grandson, who is studying mechanical engineering and would subsequently re-regulate it to suit his wearing style.)


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## xxmikexx

By the way, in the USA at least, Timex sells more watches than all other manufacturers combined, including Casio, which is a well known low end brand here. (My Timex is the replacement for an early model Casio digital that I wore for 20+ years. At the time it was a relatively pricey HAQ.) My gut guess is that the same is true at a global level -- Timex is probably by far the largest producer. (Their production is in Malasia as I recall but don't hold me to it.)

The enormous production volume of Timex watches almost certainly has allowed them to optimize their movement production, which they do entirely in house. It would not surprise me to learn that they even grown their own crystals. I will further guess that they have very advanced fast crystal timing-and-laser-trimming logic, allowing them to produce surprisingly accurate (and _very_ rugged) quartz watches at surprisingly low cost ...

... But I'm guessing.


----------



## ronalddheld

Xxmikexx please do not post any more in this thread, unless it directly involves comments the historical testing.


----------



## McAllan

xxmikexx said:


> We've been over this before ... timeanddate.com is accurate to less than 0.1 seconds according to the NIST voice clock, and it runs perfectly on the combination of Firefox and Windows XP/7, at least, and a forum member said that he checked it from his Mac and found it to be within a couple of milliseconds of NTP time. It's a good guess that it's both available to everyone throughout the year and will be accurate essentially all the time. Again, I've seen it drop ticks but I've never seen it lag or lead them.


The point is not what you're comparing with. The point is whether that your Timex is able to keep good time on it's own - which seems you missed that very important part.



xxmikexx said:


> I was speed reading but I didn't see any software button debounce logic, only a single read of a status register that gives the state of the buttons. (Or so it appeared when I was skimming.) Can you confirm that the hardware is handling debounce?


I don't know how to explain it. Seems like what I say always is misinterpreted. Has to do with the multiplexing. Works fine in reality even with cheap buttons.



xxmikexx said:


> I would probably build it without a cabinet. If gentle air currents turned out to affect temperature stability I probably would then create an ugly clock housing out of cardboard.


Build whatever you like. That's exactly the point of a kit ;-)
I prefer a nice enclosure. I don't believe whether it is or is not in an enclosure affects performance in real life because you adjust it for the conditions it has where you're using it. It's not like an enclosure is raising temperature way high to be outside the AT cuts nice temperature curve. It it did you'd severely affect longevity of all the components. The few degrees my cabinet with vent holes results in does not.
*
I get the feeling we should give Sabresoft his thread back*_. Make another thread if you want to write endless assays of what you thought I meant with a reliable time source._

Edit: Sorry moderator. I was writing when you posted. Feel free to delete this post if you feel so.


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## ronalddheld

Not to worry, McAllan it will be taken care of.


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## xxmikexx

ronalddheld said:


> Xxmikexx please do not post any more in this thread, unless it directly involves comments the historical testing.


Okay.


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## Sabresoft

Update 2013-02-24

Almost one year since the watches were reset (on DST start last year).

The Table:

View attachment 985253


The Charts:

View attachment 985256


View attachment 985258


View attachment 985261


Comparison Charts:

View attachment 985267


View attachment 985290


----------



## Sabresoft

*One Year Less a Day Test Report

*This is the end of the 2012 Test, results presented below:

View attachment 1003357


The SPY results are as follows:

Breitling Airwolf Raven -----------------> -3.35 seconds (Not too shabby)

Christopher Ward C70 Brooklands -----> -5.09 seconds (Pretty good too)

Maurice Lacroix Miros Chronograph ----> +9.83 seconds (Still respectable, but probably will adjust)

Individual charts:

View attachment 1003369


View attachment 1003370


View attachment 1003382


And the Comparison Chart:

View attachment 1003383


Not quite sure what I am going to do for my test this year just yet. I will reset all the watches today, and take an initial offset reading, but I suspect that the Breitling's battery may die soon as I have had it for 2 ½ years now, and the previous owner may have had it for a while too (unless he put a new battery in when he sold it).

Also I'd like to adjust the Miros too. I'll start a new test just in case, and see where it goes. I will probably start a new thread, as this one is becoming unmanageable, with too many branches (it took me a while to find the main thread this morning as I started to do this update).


----------



## Eeeb

Since adjustment will move these lines up or down as desired, I don't consider the absolute error rate to be the most interesting data here.

What I find revealing is the shape of the curves is pretty much identical between the watches. What this tells me is variation between individual movements is not large. Good info!!


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## ronalddheld

The shapes are similar because the TC method is the same?


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## Eeeb

ronalddheld said:


> The shapes are similar because the TC method is the same?


I am sure that is part of it. But it also shows manufacturing variation is not large.


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## Sabresoft

2013 Accuracy Test First Report

Here are charts for the Breitling Airwolf, Christopher Ward C70 Brooklands & Sinn UX

The Maurice Lacroix Miros started the test on the same day, but a few weeks ago I took my automatic version of the Miros in for regulating because it was gaining 30 seconds per day, and decided to get the TC chronograph model adjusted at the same time, so today instead of a 91 day reading it is Day 0 for the Miros.


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## Hans Moleman

Great idea!
As an illustration on how the rate varies.


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## Sabresoft

With each year's curve a little higher I am wondering if we are seeing the effects of crystal aging. If so my Airwolf and C70 are getting more accurate (until they flip to the positive side of the chart).


----------



## Hans Moleman

All your watches speed up over the years. 
My VHP has sped up so much that I try to slow it down a notch.

On the other hand MJH reports his Citizen has slowed down.
https://www.watchuseek.com/f9/citizen-a660-accuracy-report-807137.html

All possible according to the theory.

Your wearing regime remains similar over the years I guess?


----------



## ronalddheld

let me ask a "foolish" question. Do all of these watches have the exact same cut and mounting of their tuning fork?


----------



## Hans Moleman

ronalddheld said:


> let me ask a "foolish" question. Do all of these watches have the exact same cut and mounting of their tuning fork?


Nothing foolish there.
They are all ETA movements with 32 kHz crystals. That's as much as I know.

The Citizen might use different crystals. That is speculation though.


----------



## Sabresoft

ronalddheld said:


> let me ask a "foolish" question. Do all of these watches have the exact same cut and mounting of their tuning fork?


The C70 and Miros use the same ETA 7 hand chronograph caliber. The UX is a three hand non-Chrono, and the Airwolf is an Ana-Digi. All are ETA calibers (don't ask me the model numbers I can't remember them off hand and would have to look it up).

Whether the different ETA calibers have the same cut/mounting is beyond my knowledge/skill set, but I suspect that they would select and age them in a similar manner.


----------



## Sabresoft

Hans Moleman said:


> All your watches speed up over the years.
> My VHP has sped up so much that I try to slow it down a notch.
> 
> On the other hand MJH reports his Citizen has slowed down.
> https://www.watchuseek.com/f9/citizen-a660-accuracy-report-807137.html
> 
> All possible according to the theory.
> 
> Your wearing regime remains similar over the years I guess?


Currently I have 22 watches. A few are not worn much and may go up for sale (4). The rest, comprised of 4 TC, 6 RC, 1 satellite, 4 standard quartz and 4 mechanical, get worn in rotation, with the high accuracy gang (TC, RC & satellite) getting most of the wear. Usually a different watch each day.


----------



## Sabresoft

I have used my Mac's internal clock as the basis to calibrate my Skyhawk AT when doing my SPY checks on my TC watches. It is synced with 8 NTP servers. But I always wondered just how good it really was as a reference point, so I went to the time.is website and ran a check:









Not too bad, but obviously still some room for errors in my testing. Based on an assumption of initial offset reading being based on -0.006-0.037 seconds and the reading at sample date (i.e. month number in this case) based on -0.006+0.037, the following table shows the potential error impact on my SPY estimates (in seconds):









If I look at the other major components of my error (that I can actually estimate), which are the accuracy of my calibration (of the Skyhawk) and offset readings for the subject watches, using the standard deviation as an approximation of my error (the real error is probably larger, but this is a reasonable approximation), of +/- 0.016 for the calibration (average of the last four sets of tests), and +/- 0.017 for the offset readings (average from the same four tests for all the watches), the following chart shows the effect on SPY estimates:









This indicates that based on my 365 day reading my SPY assessment could be off by about 0.14 seconds (which is quite satisfactory for me), but obviously readings earlier in the year can give SPY estimates that are off by quite a bit (as much as 1.68 seconds), hence why the individual watch charts can show a lot of variability early in the test.

Put in perspective, the potential *error* of my SPY reading at 365 days is equivalent to the potential *actual deviation* of my standard quartz watches after about 6 hours, and for my mechanical watches after about 17 minutes.


----------



## Fer Guzman

Sometimes my Mac is way off from time.is, one time it was more than 1 sec.


----------



## Sabresoft

You can add more NTP servers in the Time and Date Control Panel. Currently I have:

0.ca.pool.ntp.org
1.ca.pool.ntp.org
2.ca.pool.ntp.org
3.ca.pool.ntp.org
0.north-america.pool.ntp.org
1.north-america.pool.ntp.org
2.north-america.pool.ntp.org
3.north-america.pool.ntp.org


----------



## Hans Moleman

Sabresoft said:


> You can add more NTP servers in the Time and Date Control Panel. Currently I have:
> 
> 0.ca.pool.ntp.org
> 1.ca.pool.ntp.org
> 2.ca.pool.ntp.org
> 3.ca.pool.ntp.org
> 0.north-america.pool.ntp.org
> 1.north-america.pool.ntp.org
> 2.north-america.pool.ntp.org
> 3.north-america.pool.ntp.org


NTP can take an hour to slowly tweak your computer clock back.
Your computer clock is not synched straight away.
It does need some time to do its magic.

You can follow its progress by opening a terminal and entering the command



> ntpq -p


----------



## ronalddheld

Can't you use Catalin's script to reset your PC clock?


----------



## webvan

That's what I do and it works wonders, PC only though, not MAC I believe?


----------



## Hans Moleman

I don't think NTP error rates at that high:
Check the  NTP documentation. I would guess ±10 ms would be a safe bet.


----------



## ronalddheld

I do not know if it would work on IOS since i have been on PCs for decades.


----------



## Sabresoft

Update 125 Days into 2013 Test

























The Miros test was started again 34 Days ago. The adjustment has made quite a large difference, taking it from a +8.15 SPY to a -10.4 SPY projection. I will monitor it a little longer and if the rate continues this way will readjust back half as much as before, so we may well have two restarts of this test this year. Badj = Before adjustment, Aadj = After adjustment:


----------



## Sabresoft

*153 Days into 2013 Test
*
Note that I smoothed the 2011 curves by eliminating many intermediate data points that gave the lines a very wavey shape due to the effects of week-to-week testing variability (i.e. mostly how well/poorly the idiot tester performed his testing each time, but also possibly some ambient thermal variability).









*Updated Charts*

























The three charts above show a definite upwards shift, from year-to-year, of the test curves. I wonder if this is an indicator of crystal aging.

For the Breitling, the shift was about 4.6 SPY from 2011 to 2012, and looks to be about 3.2 SPY from 2012 to 2013.

For the ChristopherWard, the shift was about 2.9 SPY from 2011 to 2012, and looks to be about 3.0 SPY from 2012 to 2013.

For the Sinn, the shift was about 1.5 SPY from 2011 to 2012, and looks to be about 2.9 SPY from 2012 to 2013.

Not sure if any conclusions can be drawn yet, but worth watching in the future.









Can't draw any inferences from the Miros because of the multiple restarts (dead battery in 2011, adjustment this year).

*Comparison*

Finally the comparison chart for all the watches.









As a matter of interest, while I dropped the Precisionist from the comparison after 2011 because of the pretty much outside of COSC performance that year, a qualitative assessment indicates that it would probably be running at around 40-50 SPY this year. A far cry from the 10 SPY that Bulova still claims. Now realistically their claim may really be based on a regular wearing regime (even if they deny it), but none of my HAQ watches gets worn daily as they are part of a rotation of a reasonably large collection. As I generally alternate between 4 HAQ and 5 RC watches during weekdays, with other watches thrown in on occasion (i.e. My Campanola yesterday) any one of these watches probably sees wrist time about once every two weeks, and yet all the HAQs are showing good performance (certainly within COSC for my 'worst', the Sinn UX).


----------



## Eeeb

I think it interesting the curves of the various watches seem to adopt the same shape. If they are exposed to the same environment I suspect you are seeing the effects of the TC algorithm.


----------



## ronalddheld

How much is due to TC environmental yearly effects and aging?


----------



## Eeeb

ronalddheld said:


> How much is due to TC environmental yearly effects and aging?


Aging would result in a shift of the whole curve, up or down.

TC<=>environmental effects would change the shape of the curve.


----------



## Sabresoft

Eeeb said:


> Aging would result in a shift of the whole curve, up or down.
> 
> TC<=>environmental effects would change the shape of the curve.


Would aging be a shift in either direction or just in one direction? Mine all seem to be gaining each year.


----------



## Eeeb

Sabresoft said:


> Would aging be a shift in either direction or just in one direction? Mine all seem to be gaining each year.


Aging would shift in one direction if the crystal cut is the same... I believe.


----------



## Hans Moleman

Eeeb said:


> Aging would shift in one direction if the crystal cut is the same... I believe.


The crystal documentation mentions that aging can be in either direction.
I can't find the post, but we've had reports about a The Citizen that slows down over time.
All the ETA movements seem to speed up.

Wrong, I did find it: The Citizen report is here.


----------



## Eeeb

Hans Moleman said:


> The crystal documentation mentions that aging can be in either direction.
> I can't find the post, but we've had reports about a The Citizen that slows down over time.
> All the ETA movements seem to speed up.
> 
> Wrong, I did find it: The Citizen report is here.


I think there is not enough data to draw any conclusions here...


----------



## Hans Moleman

Eeeb said:


> I think there is not enough data to draw any conclusions here...


Agreed.
Temperature effects easily account for a few seconds per year.


----------



## Sabresoft

Temperature effects are tricky to account for. Temperatures vary continuously, and short of taking regular offset readings (say hourly) charted against the average temperature gradient over the hour, it would be difficult to define what impact that temperature actually has on a given watch. 

A wholesale, parallel shift of the curve would seem to me to be indicative of crystal aging, while lines that bounce around with varying gaps might be more indicative of inter-year temperature gradient effects. 

I suspect that my curve shifts are mostly showing crystal aging effects.


----------



## Hans Moleman

Sabresoft said:


> Temperature effects are tricky to account for. Temperatures vary continuously, and short of taking regular offset readings (say hourly) charted against the average temperature gradient over the hour, it would be difficult to define what impact that temperature actually has on a given watch.
> 
> A wholesale, parallel shift of the curve would seem to me to be indicative of crystal aging, while lines that bounce around with varying gaps might be more indicative of inter-year temperature gradient effects.
> 
> I suspect that my curve shifts are mostly showing crystal aging effects.


I just hope you'll be doing your measurements for a few years yet!
It gives us such a wonderful graphic illustration of what a rate does over time.
They are so easy to read.

If all years show this upward movement that would make a compelling case.

I hate to think about the effort that goes into it though.


----------



## Sabresoft

Hans Moleman said:


> I just hope you'll be doing your measurements for a few years yet!
> It gives us such a wonderful graphic illustration of what a rate does over time.
> They are so easy to read.
> 
> If all years show this upward movement that would make a compelling case.
> 
> I hate to think about the effort that goes into it though.


Well in the early tests (i.e. 2011) I was doing updates almost weekly (hence all the erratic readings), but since then my readings have dropped to monthly or longer intervals. Only 4 watches to monitor so it isn't too bad, and rather a fun exercise. The biggest negative is that I frequently forget to set my Skyhawk (used for the timing) back to time or calendar mode from Chrono mode, which then results in a failure to sync with the atomic clock. Minor really, but happens frequently.


----------



## Sabresoft

All this talking about temperature and aging got me to thinking about putting all my data into one line (i.e. 2011, 2012 & 2013). I did this for the Airwolf and C70 Brooklands:









The lines generally trend upwards, supporting the aging concept. The peaks are during the summer months, and the valleys during the winter months, which would be a measure of thermal effects. Discounting the days when the watches get worn, generally the winter temperatures are 20C during the day and 16C over night (based on a programmed thermostat). The summer temperatures vary more widely as we generally are affected by outside weather temperatures, but the thermal range is probably between 18C (on a cooler night) to 30C on a hot day.


----------



## Hans Moleman

Sabresoft said:


> All this talking about temperature and aging got me to thinking about putting all my data into one line (i.e. 2011, 2012 & 2013). I did this for the Airwolf and C70 Brooklands:
> 
> View attachment 1189441
> 
> 
> The lines generally trend upwards, supporting the aging concept. The peaks are during the summer months, and the valleys during the winter months, which would be a measure of thermal effects. Discounting the days when the watches get worn, generally the winter temperatures are 20C during the day and 16C over night (based on a programmed thermostat). The summer temperatures vary more widely as we generally are affected by outside weather temperatures, but the thermal range is probably between 18C (on a cooler night) to 30C on a hot day.


Good idea! A graph for a single three year period.

It could still be three years in a row that all were hotter than the previous year.
:think:

Well, I had to recalibrate my VHP. A tentative admission towards aging.


----------



## ronalddheld

I think it is a good idea to periodically see the cumulative data on a single graph.


----------



## Sabresoft

Hans Moleman said:


> Good idea! A graph for a single three year period.
> 
> It could still be three years in a row that all were hotter than the previous year.
> :think:
> 
> Well, I had to recalibrate my VHP. A tentative admission towards aging.


While I don't have actual temperature records year-to-year, I am fairly certain that this year was not warmer than last year. This summer we started off the first day really hot but it was all downhill from there, and last winter, just judging by my gas consumption, it was colder, longer, than the previous year.


----------



## ronalddheld

Since aging was discussed this may be of interest.


----------



## Sabresoft

*Day 176 in 2013 Test*

Just a simple comparison chart this time.


----------



## Sabresoft

*Update September 28, 2013*

I have made a small change to my charts, and that is to include the end-of-last-year SPY value as the estimate value at day zero for the subsequent year curve. Sort of like my continuous chart, but more compact.


----------



## Sabresoft

Day 230 Update

Comparison chart today. The curves are starting to bend downwards as the colder weather takes over.


----------



## Sabresoft

*Day 288*

Charts for the Breitling Airwolf Raven (288 Days), Christopher Ward C70 (288 Days), Maurice Lacroix Miros Diver (197 Days) and the new Certina DS2 (24 Days). The Sinn UX test was also restarted when the new Certina test was started, but I must have recorded an incorrect initial offset because the results for the UX don't make any sense. I will therefore abandon the UX test until I do a restart of all tests at DST start in March 2014.

Currently the Airwolf is projecting a -0.27 SPY, the C70 a -4.10 SPY, the Miros a -12.91 SPY and the DS2 a -3.22 SPY.






























Just prior to starting the 2014 test I will adjust the Miros (back half as much as it was adjusted earlier this year) so that it should run pretty close to less than 2 SPY.


----------



## Sabresoft

*Day 321 Update

*Here are the latest charts:


























No UX this time because I messed up the initial offset reading. Will restart in March when I reset all the other watches.

Finally the comparison chart:









Clearly three great looking (TC wise) watches, one that needs adjustment (Miros), and the UX is till within COSC, just not as accurate as the rest.


----------



## Sabresoft

*End of 2013 Test & Start of 2014 Test*

Well here are the final updates for the 2013 test. Only 3 watches made it to the end. The restart of the UX test in November at the non-DST time change was botched by a bad recording of the initial offset. The test on the DS2 was botched last week when advancing the date for Feb 28 --> March 1, when the crown was accidentally pulled out two clicks.

So here are the results for the Breitling Airwolf Raven, the Christopher Ward C70 Brooklands. The curves for the first year in the test were shifted to reflect the start date happening later in the year, which makes the year-over-year comparison better matched. The UX chart is not uploaded at this time as it hasn't changed from the last one posted earlier.

















The following chart shows the comparison of all five watches for the 2013 test. Despite the error last week with the Certina DS2, I projected the line to this week using a trend line feature (it won't be too far of correct I suspect).








The final chart is what I am calling "Apparent Aging Effect". For the 3 watches that I have somewhat consistent results for 3 years (Airwolf, C70 and UX) I have done a comparison of the shifts in the SPY curves from year-to-year. This may be a measure of the aging effects on the crystal, although since there is no control over the temperature envelope or wearing regime over the years there is no way to say that this is a true measure. I just post the chart as a matter of curiosity.









The 2014 test starts today, with the watches set with the following offsets:

Airwolf 1.05 seconds (same as the end of 2013 test, i.e. no reset)
C70 1.54 seconds (an attempt at -1/2 of last year's end SPY value)
Miros 4.60 seconds (an attempt at -1/2 of last year's end SPY value)
UX -5.37 seconds (-1/2 of DST period gain)
DS2 1.79 seconds (an attempt at -1/2 of last year's end SPY value)

I have a suspicion that the Airwolf and C70 won't make it through the year, because both must be getting near to the end of their battery lives.

Also despite starting the test with the Miros, I do plan on adjusting it to bring it closer to zero, as last year's adjustment was too much.


----------



## Josef01

Very nice long long test!


----------



## Sabresoft

*2014 Test Day 84 Update*

_*Breitling Airwolf Raven*_

Currently showing a projected 2.17 SPY estimate (see Interesting Observation below for comments).









_*
ChristopherWard C70 Brooklands*_

Currently showing a -2.59 SPY estimate.









_*
Maurice Lacroix Miros Diver Chronograph*_

Despite an adjustment at the start of this year's test, it appears to be projecting a similar SPY to last year. Current estimate is -9.90 SPY.









_*Certina DS2*_

Looking good, with estimated -3.01 SPY.









_*Sinn UX*_

The worst of my TC watches with an estimated 21.34 SPY. Hopefully at battery change time I can convince Sinn to adjust the watch.









_*Interesting Observation*_

Just for a little fun I looked at the SPY projections for the Airwolf Raven in the 2012 and 2013 tests, and plotted the SPY estimates by calendar month as a percentage of the end of year "real" SPY value (i.e. actual measurement at 365 days). Both years the early projections (March) were 60% below the final value and in August-September time frame were about 35-45% above the year end value. Initially when starting to play with the data I expected to see year end and year start data about the same, but I suspect that the year end data being higher is primarily due to aging effects.


----------



## Hans Moleman

I think your estimates are out because they don't factor in the temperature variations over the year.
The estimates are lower in March since its colder than usual.
They are higher in June as its warmer than usual.

If that was what you meant.

The resulting yearly SPY value isn't meaningful. It all depends on what sort of temperatures you've had during that year. A matter of luck.

The Maurice Lacroix Diver seems to go against the trend over the years.
Where all the other ETA movements speed up or slow down, it does the opposite.

Does not make the story a lot easier... 

Love the graphs!


----------



## Sabresoft

Hans Moleman said:


> I think your estimates are out because they don't factor in the temperature variations over the year.
> The estimates are lower in March since its colder than usual.
> They are higher in June as its warmer than usual.
> 
> If that was what you meant.
> 
> The resulting yearly SPY value isn't meaningful. It all depends on what sort of temperatures you've had during that year. A matter of luck.
> 
> The Maurice Lacroix Diver seems to go against the trend over the years.
> Where all the other ETA movements speed up or slow down, it does the opposite.
> 
> Does not make the story a lot easier...
> 
> Love the graphs!


The higher values are definitely in the summer, but each year the March reading (DST) at the end of the test is higher than the value in March at the start of the test, which leads me to believe that the difference is partially due to aging.

As to the Miros, it is all over the map because I have been adjusting the watch, so I have yet to get a full year test that is complete. The SPY estimate this year is around 8 seconds, so while it could do better, I will leave well enough alone this year so that i can get a full year test, and then adjust it again next March.


----------



## Sabresoft

*Day 133 in 2014 Test*

This month I am presenting a comparison chart for all 5 watches:









The Breitling and Christopher Ward continue to perform well, the Certina despite not being a COSC tested/certified model is also doing very well. The Maurice Lacroix is currently showing an 8 SPY estimate, but probably will be about 10 SPY at the end of the test. The Sinn is fairly steady at about 22 SPY.

SPY values are nice statistical estimates of watch accuracy, but don't really tell the story at any given point in time. Just for fun I have plotted up actual offset readings for two of my watches over the 2012-2013-2014 test period.

The Breitling Airwolf Raven chart follows:









Basically, including my negative offset at the beginning of the 2013 test (I opted not to adjust the watch this year), the watch has been within +2/-1 seconds of correct time at any point in time. If I had not done the adjustment in March 2013, the watch would still have been within +2/-2 seconds of correct time. To me that is pretty good performance.

The Christopher Ward C70 Brooklands chart:









With the negative offset adjustments at the start of both the 2013 and 2014 tests, the watch has been within approx. +/- 2 seconds of correct time at any point in time. Had I not done the two offsets the watch would be running at about -8 seconds, which is still pretty good.

While the UX is running in the 20-22 SPY range, because of needing to reset the watch at both DST change periods, based on the watch offset data for 2012 and 2013 the watch has been between -5 to +7 seconds of correct time. A larger negative offset would have yielded +/-6 seconds.


----------



## igna

Hi.

Great work.
Just bumping & asking if you still testing them.

Regards.


----------



## ronalddheld

Another month before my yearly watch checking.


----------



## Sabresoft

igna said:


> Hi.
> 
> Great work.
> Just bumping & asking if you still testing them.
> 
> Regards.


Yes. Just been busy and then sick of late. Have pneumonia, and am slowly on the mend.


----------



## ronalddheld

Sabresoft said:


> Yes. Just been busy and then sick of late. Have pneumonia, and am slowly on the mend.


Fully recover first. We will wait.


----------



## igna

ronalddheld said:


> Fully recover first. We will wait.


Sure, we will wait.

Btw, the reason I finally went for a HAQ was this forum, and I come here thanks to your accuracy tracking post (after a google search). All was so interesting I keep reading many other post. So, at a certain degree you are responsible of now being a HAQ fan. b-)

Get well.


----------



## rdwatch

I just saw this post, and have some info on the following watches that I've purchased this year that some folks may have an interest in.

I need to get my spreadsheet data put together, but I've been tracking these watches since new, and some of you may own some (or alot! of them), and may have an interest. All the automatics have been purchased over 2014 from January onward.

Here's the watches - 

Steinhart - 

OV1
GMT Vintage

Seiko
007
009

Orient
SER2002W - (DJ homage)
MakoII - (white lume face)

Squale
Root Beer Bezel

Bernardt
BBAii

Casio 
MDV 106 (it's a quartz Diver, and is dead on accurate over the first 30 days, but am including it)

2 Old quartz Swiss Army/Military watches from 1998 and 2002 that are still running, both still very accurate.

Will post later with those numbers, and how long I have been tracking them.


----------



## hughesyn

rdwatch said:


> I just saw this post, and have some info on the following watches that I've purchased this year that some folks may have an interest in.
> 
> I need to get my spreadsheet data put together, but I've been tracking these watches since new, and some of you may own some (or alot! of them), and may have an interest. All the automatics have been purchased over 2014 from January onward.


Nice collection, but it doesn't look like you have any high accuracy quartz there.

To put in perspective, Sabre's worst performer is about 20 sec per year and best is 2 sec per year.
If you can get anywhere near those figures we'd be interested!


----------



## rdwatch

hughesyn said:


> Nice collection, but it doesn't look like you have any high accuracy quartz there.
> 
> To put in perspective, Sabre's worst performer is about 20 sec per year and best is 2 sec per year.
> If you can get anywhere near those figures we'd be interested!


You Sir, are correct!

I was just checking in, and misread the post, sorry about that!

Too many football brewskies I guess!

But, I do like the quartz watches quite a bit.

Being a mechanical geeker type, I also like the mechanicals, but for pure ease of use and accuracy, quartz if simply great.

So, my Swiss Army (1998 Lancer 100) is well within 20 secs per year (about 12 or so), and the 79100 Chrono Swiss Military (2002 vintage) is still about 1 sec every 3 months or so. I've only put batteries in these, no service whatsoever as they only cost me about $100 each at Costco and BJ's back in the day. Haha! What did I know? Just liked the styles. These guys are my "beaters" now, although I still like them!

And, the Casio "38 Special" (cost me $38 Amazon) has not gained or lost anything in the month I've owned it. Go figure.

Well, glad to be on this post as I will look forward to seeing the results posted......


----------



## rdwatch

hughesyn said:


> Nice collection, but it doesn't look like you have any high accuracy quartz there.
> 
> To put in perspective, Sabre's worst performer is about 20 sec per year and best is 2 sec per year.
> If you can get anywhere near those figures we'd be interested!


hughesyn, not sure if this has any meaning to you folks, but I did say I would post the results -

Quartz -

Swiss Army Lancer 100, purchased 1998, no servicing except battery replacements ---- +.6 secs per day over past 3 months

Swiss Military 79100, purchased 2002, no servicing except battery replacements ---- 0 secs per day over past 3 months

Casio MDV106, purchased Oct 2014, ---- 0 secs per day over past 2 months

Summary on the Automatics - (Purchase Dates under descriptors)


----------



## ronalddheld

Please no more posts of mechanicals and non HAQ quartz watches in this thread. That can go in the Public Forum.


----------



## PeterG_SVK

I haven't read all topic and thought it's for everyone tracking reports, so my apologies to Sabresoft if I hijacked his thread for some time, so I deleted the post.


----------



## igna

Congratulations, Very good performance, specially the black dial Longines.

This topic is for anyone accuracy tracking report, I'm tracking the GS and was wondering if I have to start a new topic, or if I can post here, in Sabresoft thread?


----------



## PeterG_SVK

I haven't read all topic and thought it's for everyone tracking reports, so I removed my previous post.


----------



## Sabresoft

igna said:


> Congratulations, Very good performance, specially the black dial Longines.
> 
> This topic is for anyone accuracy tracking report, I'm tracking the GS and was wondering if I have to start a new topic, or if I can post here, in Sabresoft thread?


No, as Ronald indicated it is primarily for my tracking reports, and comments thereto. If you want to show your own results in response to one of my posts that is fine, but primarily it is my thread.


----------



## Sabresoft

*Day 301 in 2014 Test
*
Breitling Airwolf









ChristopherWard C70









Maurice Lacroix Miros









Sinn UX









Certina DS2









I have been thinking about a comment made by Hans Moleman a few weeks back about the affects of warmer and cooler seasons on the SPY estimates. As can be seen on my charts the curves always trend upwards as we move away from the start date (March DST start) and then as we approach March again in the following year the curves trend back down. If I started my tests in August/September the curves would trend down and then back up again.

I played with my data for the Breitling a little and came up with SPY estimates at 365 days based on my current 2011, 2012, 2013 and 2014 results, but also looked at the data as though it started at the 202 day period in each of my tests. I chose 202 days not because it was necessarily the highest value, or a half way point (which it isn't), but because it was one point that was pretty much common in all my tests (204 days for 2014 tests). So the September data was based on readings taken from September 2011-2012, etc.

As can be seen from the table and chart below the 365 day offset (SPY value) moves up and down based on the data start point. The curved data line is not really appropriate, but I didn't want to fool around with mixing a curve and bar graph. The other data line is for the average of SPY estimates in each period (i.e. the average of all the data points for the sample period). This data line pretty much supports the idea of aging effects, but I was expecting it to pass through a point closer to midway between the high and low points of the SPY estimate values. Sampling frequency may have something to do with this as I don't do my tests on a regular basis, but rather when I find time or inspiration.


----------



## igna

The last graphic is the Airwolf Raven concatenated? 
It stops in Sep/2014, shows a nice repetitive pattern.


Thanks for the info!


----------



## Sabresoft

igna said:


> The last graphic is the Airwolf Raven concatenated?
> It stops in Sep/2014, shows a nice repetitive pattern.
> 
> Thanks for the info!


The post wasn't quite complete when I posted it. I had done the complete update and then when I went to post it, got a message saying that I didn't have permission and needed to log in, so I lost it all. I quickly rebuilt it, but before I had pot in the last part of the write up got called by the wife to come for dinner so I quickly posted what I had in order not lose it all again. After dinner and a trip to do some grocery shopping I came back and updated the post.

Basically the high points on the curved line represent SPY estimates at the end of a period Sept 2011-2012, 2012-2013 etc. and the low points represent the old 365 day data (i.e. March 2012, 2013, 2014) as covered by my regular charts that I post. And as I indicated in my explanation in my post above the curved line is not really appropriate for displaying that data because it is not really a continuum, but rather discrete data points. That said intermediate points along the curves might be a good proxy for what I could expect to see if I did say a July-July or November-November data collection.

When I have time I will explore this in a little more detail and also look at the same thing for the CW C70, which is the only other watch with a complete set of data for the 2011-2014 period.


----------



## Sabresoft

*Day 343 in 2014 Test

*


----------



## Sabresoft

*The possible aging effects chart*


----------



## Sabresoft

I have plotted some charts showing actual offsets instead of projected SPY for several of the watches. Basically it shows how close to "accurate" time each of the watches were during the year.

Breitling:








ChristopherWard:








Maurice Lacroix:







Note that the Miros was adjusted between 2012 and 2012 to slow it down (too much as it turns out), so this year it will get adjusted again.


----------



## Sabresoft

*2014 Test Completion (365 Days)
*
The 2014 SPY Test is complete, with charts shown below.

Breitling Airwolf Raven

At the end of the test the Breitling had gained 1.46 seconds. I am amazed that this watch is still chugging along on its original battery from 2010.










ChristopherWard C70 Brooklands

At the end of the test the ChristopherWard had lost 4.88 seconds. Quite impressive performance too.









Maurice Lacroix COSC Miros Diver

At the end of the test the Maurice Lacroix had lost 7.77 seconds. This one will be adjusted again this year to see if I can get it down to within +/- 5 seconds.









Sinn UX

At the end of the test the Sinn had gained 17.64 seconds. Definitely hope that Sinn will adjust at battery replacement time in about 3-4 years from now. By then it will be outside COSC specs judging by the aging effects of the last few years.









Certina DS2 Chronograph

At the end of the test the Certina had lost 3 seconds. Very impressive performance, even without the COSC "diploma".


----------



## Sabresoft

*2015 Test Start*

I decided this year not to bother with the negative offsets at the start of the test (i.e. minus 1/2 of last year's SPY value at the end of the test). All watches were set "accurately". An initial offset reading was done for each watch to account for setting error, as can be seen in the chart below.









This error primarily comes from reaction time when clicking crown in for the watch being set. The standard deviation on these initial readings was between 0.013 (DS2) and 0.02 (Airwolf and Miros). The C70 was 0.016, and UX 0.014. Assuming that the 365 day reading would have a similar standard deviation (I aim for 0.02 or better, sometimes settling for as high as 0.025), the "error" effect on the year end SPY number would be in the order of +/- 0.030 to +/- 0.05 seconds. Not really significant, but early SPY estimates will be affected much more by these small errors, hence why I don't start charting the SPY estimates until 30-45 days into the test.

I collect and average at least 6 readings for each watch, aiming to keep the standard deviation in that ≤0.02 region. After the initial 6 readings are taken I replace high and low values with additional readings until the standard deviation closes in on the desired value (that's why some times I'll settle for as high as 0.025 because I can't get it to converge as much as I'd like it to).

One of the charts that I will present this year will be an actual offset for each watch (adjusted for initial offset) to show how far off "correct" time that each watch is at a given point in the year.


----------



## Sopur

Sorry, I did not read the entire threat, but for all Android users: you can find the app watchheck on the Ansroid market for free. It s in German but self explaining. To measure the accuracy of any watch! Very usefull tool!
Best regards
Sopur

Gesendet von meinem D5503 mit Tapatalk


----------



## webvan

Thanks for the hint, it look like a quality app. For quartz watches an averaging feature on x measurements would be a +


----------



## webvan

Been using WatchCheck for a few weeks now and it is turning out to be a very convenient app indeed. Beats using Excel and hunting for cells and doing time calcs 

Possible improvement would be to select date ranges to check variations based on the season/temperature.


----------



## Sabresoft

*Day 114 in 2015 Test Report*

Here are my test results at day 114 in 2015 test:

*Airwolf
*








*C70*








*DS2*







*
UX
*








All looking similar to last year with small shifts due to aging effects. And then there is the Miros. The last time it did this, the battery died a few weeks or months later, with the watch accelerating days fast during the last few hours before the battery died completely. The last battery replacement was in 2012. The C70 battery died and was replaced early in the 2014 test, and the Airwolf is still on its original battery, and so too is the UX!


----------



## Sabresoft

_August 2015 Update_

Latest charts from my tracking effort:








The Breitling's battery is in it's death throws, with the UEL flashing in the upper display. Just waiting for my watch maker to get the new battery in as she had to special order it. For a battery that is only supposed to last 2-3 years, I have managed to get a solid 4 years out of it, so I'm quite happy, especially with the high accuracy that the watch has maintained.








This watch is continuing to display quite satisfactory accuracy.








Also very impressed with the performance of this watch.








Love this watch, but it is dangerously close the breaching the COSC upper limit, which it may well do before the 8 year battery needs replacing. Still at that time I should be able to convince Sinn to adjust the mechanism.








The battery finally died and was replaced. At that time my watchmaker adjusted it to speed it up slightly. The hump in the curve will be eliminated the next time that I do an update. Just wanted to show that the watch should be back on track for a better performance, as that 80 SPY due to the battery dying is definitely not indicative of the potential for this watch.


----------



## dmmartindale

Sabresoft said:


> _August 2015 Update_
> 
> Latest charts from my tracking effort:
> 
> View attachment 5021969
> 
> The battery finally died and was replaced. At that time my watchmaker adjusted it to speed it up slightly. The hump in the curve will be eliminated the next time that I do an update. Just wanted to show that the watch should be back on track for a better performance, as that 80 SPY due to the battery dying is definitely not indicative of the potential for this watch.


I am very surprised by the shape of the "hump" in the Miros Diver graph. Taken literally, it shows the watch rate slowing slightly for the first 50 days of the year, then slowly and almost linearly increasing for 80 days or so, then taking another 50 days to return to normal after the battery was changed. I would expect that the actual data showed that the watch ran consistently until the battery voltage dropped, that the rate just increased at that time *without* first decreasing, and that after the battery change the rate was instantly back to normal without taking 50 days to return to normal.

I've seen this sort of problem before, and it's generally the result of graphing the data with a program (e.g. Excel) that wants to draw a smooth line through the data points, even when the data is not smooth. The data is interpolated with a function that looks like a sin(x)/x function, or a cubic spline, and when the input looks like a sudden pulse (e.g. consistent readings, then one or two high values, then a return to the previous values) the interpolating function "rings", producing an undershoot before the edge, probably an undershoot after the edge, and the appearance of a smooth change that is not supported by the data. I'll bet that the shape in the graph was created by the graphing software. And the smooth line hides the positions of the actual data points, so we can't tell what the real measurements were.

One way to fix this is to just turn off line smoothing in the graph, if you can. Then we would see an abrupt jump upward as the battery died, and a (possibly more abrupt) jump back to normal after the battery change. The graphing program will still draw straight lines between the data points, which will still not be exactly correct (a true graph would show an instantaneous drop at the battery change), but a straight-line interpolation will show where the data points are for any large change, and the human mind can ignore the line and realize what really happened.

On the other hand, if you really like the smooth-looking graphs, you could have the graphing program mark where the data points are with crosses or stars or something. Then you could still have the smooth line, but people like me could look at the data points and ignore the smooth line.

I frequently use Excel to graph data and functions of various sorts. I never, ever, use the line smoothing feature. If a graph of a calculated function looks too coarse, I re-arrange the data to calculate the value more frequently, until the result looks smooth. Then I have a smooth-looking graph based on actual calculations of the function, not some interpolated smoothed curve that isn't correct. If I'm graphing real data, a non-smooth graph just shows the level of noise in the measurements (and may suggest that I need to take measurements more frequently).

- Dave


----------



## Sabresoft

I know that the chart is weird looking, but as I stated at the time that I posted it, I just wanted to indicate that the watch was back to normal performance (or so I hope, as I only have an initial reading for the post battery test. I was just too lazy, and somewhat time constrained when I updated the chart. Next update will fix that. Usually I just start a new line/curve for the post battery test, as trying to continue the original 2015 test is somewhat difficult with no frame of reference for the discontinuity (I have no record of exactly when the battery died). Also I had the watch adjusted during the battery change, so it is best to start a new line/curve.


----------



## Sabresoft

Also the dip just before the "death" climb is from an early reading, so is very likely to be reflecting the large error of extrapolating SPY from short duration data.


----------



## Sabresoft

What I find interesting is that both times the Miros' battery has died the curve climbed steeply like shown, but the ChristopherWard C70 which uses the same calibre did not behave similarly when its battery died.


----------



## Sabresoft

Sabresoft said:


> What I find interesting is that both times the Miros' battery has died the curve climbed steeply like shown, but the ChristopherWard C70 which uses the same calibre did not behave similarly when its battery died.


Well the battery in the Airwolf finally came close to it's end seeing the flashing UEL in the upper display for over a month now (had to wait for my watch repair lady to order in the battery).

The battery lasted over 4½ years (I've had it since December 2010, and it was owned privately prior to that, so the battery was in there for a while, the listed life expectancy is 2-3 years).

Tested the "sleep" feature whereby you can put the watch in a temporary sleep mode and you have about 15 seconds to replace the battery without losing all the memory/settings. It worked like a charm, and the SPY chart really doesn't show anything significant. To invoke this sleep mode, put the digital displays to off (except UEL flashes on the upper display when the battery is low), then pull the crown out one click and press the upper chrono button until the displays go blank and the second hand stops moving. Once the battery is replaced, push the crown back in and the watch resumes where it left off.

Unlike the Miros, there was no death climb in the SPY estimate with this watch as the battery failed.


----------



## ronalddheld

Sabresoft said:


> Well the battery in the Airwolf finally came close to it's end seeing the flashing UEL in the upper display for over a month now (had to wait for my watch repair lady to order in the battery).
> 
> The battery lasted over 4½ years (I've had it since December 2010, and it was owned privately prior to that, so the battery was in there for a while, the listed life expectancy is 2-3 years).
> 
> Tested the "sleep" feature whereby you can put the watch in a temporary sleep mode and you have about 15 seconds to replace the battery without losing all the memory/settings. It worked like a charm, and the SPY chart really doesn't show anything significant. To invoke this sleep mode, put the digital displays to off (except UEL flashes on the upper display when the battery is low), then pull the crown out one click and press the upper chrono button until the displays go blank and the second hand stops moving. Once the battery is replaced, push the crown back in and the watch resumes where it left off.
> 
> Unlike the Miros, there was no death climb in the SPY estimate with this watch as the battery failed.
> 
> View attachment 5091906


Is the sleep mode built into all analog-digital Superquartz modules?


----------



## chris01

ronalddheld said:


> Is the sleep mode built into all analog-digital Superquartz modules?[/QUOTE
> 
> Not the B79 Aerospace. I can'tspeak for the other SQs.


----------



## ronalddheld

chris01 said:


> ronalddheld said:
> 
> 
> 
> Is the sleep mode built into all analog-digital Superquartz modules?[/QUOTE
> 
> Not the B79 Aerospace. I can'tspeak for the other SQs.
> 
> 
> 
> My Aerospace is fairly old so I thought it might be a more recent addition.
Click to expand...


----------



## Sabresoft

ronalddheld said:


> chris01 said:
> 
> 
> 
> My Aerospace is fairly old so I thought it might be a more recent addition.
> 
> 
> 
> I'm not sure because the Airwolf (Breitling B78 caliber) uses the chrono pusher to initiate the mode. I only discovered this recently. Not sure where, but probably on the Breitling forum. With the crown only models I'm not sure how you'd initiate that feature.
Click to expand...


----------



## ronalddheld

Sabresoft said:


> ronalddheld said:
> 
> 
> 
> I'm not sure because the Airwolf (Breitling B78 caliber) uses the chrono pusher to initiate the mode. I only discovered this recently. Not sure where, but probably on the Breitling forum. With the crown only models I'm not sure how you'd initiate that feature.
> 
> 
> 
> I suppose I could also go and ask my Breitling AD about it.
Click to expand...


----------



## Sabresoft

*Day 238 in 2015 Test & DST Off Day*

Well it is Day 238, the end of DST for this year and the end of the test for the UX as I have to reset the watch to drop back one hour.

Here are the test charts updated to today:

*Breitling Airwolf Raven*








Still showing pretty good performance, but is definitely showing aging effects.

*ChristopherWard C70 Brooklands

*







One of my best on performance, and aging effects seem to be less than for the Airwolf.

*Maurice Lacroix Miros Diver*








Doing OK, but could still be better. If I adjust again, it seems that I won't get two full years of testing in a row, what with adjusting and battery replacements.

*Certina DS 2*








This one looks great. The most accurate of my collection.

*Sinn UX*








Close to not being within COSC, and if aging effects continue, will probably be outside of COSC spec next year. Definitely will need adjusting when it goes back to Sinn for a battery replacement in the next few years.


----------



## Sabresoft

I did an update a few days ago, Day 294. I am not going to show the charts for couple of reasons:

1. I'm too lazy to do al the work right now;
2. There have been no significant changes since the last test.

But one of the main reasons that I like TC watches (and RC & GPS) is that they are basically grab and go watches that I can have reasonable confidence in being accurate or within a small range of accurate.

In that vein, I have done a quick sampling of my watches to see just how accurate they are right now:








All of the main "accuracy gang", TC, RC and GPS are within 5 seconds of being exact.

The standard quartz are definitely less so, and my Alpha, well, needs to be reset each time if I choose to wear it.


----------



## Sabresoft

*March 13, 2016 DST Update*

My "year end" charts follow:

*Breitling Airwolf** (6.26 SPY)
*
View attachment 7424802


*Christopher Ward C70 Brooklands** (-3.06 SPY)*

View attachment 7424810


*Maurice Lacroix Miros COSC Chronograph Diver** (-7.63 SPY)*

View attachment 7424826


*Sinn UX** (21.2 SPY)
*
View attachment 7424850

*
Certina DS2 PreciDrive** (0.93 SPY)

*
View attachment 7424874


----------



## Sabresoft

OK, why aren't my charts showing up in-line as they always do normally? Still they are in the message.


----------



## Hans Moleman

Sabresoft said:


> OK, why aren't my charts showing up in-line as they always do normally? Still they are in the message.


I always prefer the 'Insert Image' button:








It inserts just the one image at the cursor.

I avoid the above 'Attachments'. That button adds all selected attachments, together, at the end of the post.


----------



## Sabresoft

Hans Moleman said:


> I always prefer the 'Insert Image' button:
> 
> View attachment 7434298
> 
> It inserts just the one image at the cursor.


That's what I used, and have always used. But this time I just got the underlined links.



Hans Moleman said:


> I avoid the above 'Attachments'. That button adds all selected attachments, together, at the end of the post.


I only used that after, when I edited the message later, just to get the images showing in the message.

Basically I put the message together the way I have always done it and got a rather strange result this time. Hopefully this was just a passing hiccup!


----------



## Michael Reichmann

*Certina DS2 PreciDrive** (0.93 SPY)*

This is truely astonishing performance. I'm impressed and pleased because I have a Certina DS-8 on order, due to arrive any day.

My Breitling Airwolf and Omega X-33 Gen 2 have both been in the 5-10 SPY range for the past few years.

When the DS-8 arrives I'll set the three to a time signal and then make a note to come back in a year for a comparison. (I might sneak a peak in 6 months though).

Michael


----------



## Sabresoft

*DST OFF UPDATE*

I haven't been doing much updating of this thread this year. For a couple of reasons, including I have just been to busy (hence only a few readings this year), and also the test results have been a little disturbing.

My Airwolf definitely seems to be getting worse, having popped over the +10 SPY mark.









The C70 has also shown a marked increase in number after many years of being very good. This could be because the battery may be starting to go, like in the Miros, but the Miros drift got exponentially higher just before finally quitting, the C70 seems to be levelling off. Will just have to watch and see what happens:









The UX started showing slightly better performance but has now upticked towards its usual numbers:









The Miros looks like it is doing quite well this year unlike most of the other watches:









And the DS2 still looks good, even despite the later year uptick similar to several other watches this year:









Not sure what to make of these charts this year. Initially I thought that my test start readings could have been off, but if they were, then most of the watches would be showing exactly the same behaviour, and they really aren't.

The Breitling definitely has shown a fairly consistent increase each year, which I would say looks to me like evidence of crystal aging. Generally all the watches are showing a drift upwards. The Miros doesn't quite show this trend because it has been adjusted several times. But right now it looks pretty good, so I won't be playing with that it anymore.


----------



## Sabresoft

*2016 Test Year End Report*

Here are the charts for the year end of my 2016 test.

The Breitling has shifted up yet again (aging effects?). Still within reasonable range, but might need an adjustment soon. See what happens this year.









The ChristopherWard has definitely suddenly accelerated upwards. This might be similar to what happened with the Miros a few years ago, which was a sign of the battery dying. I'm not sure, but I don't recall if I ever replaced the battery in this watch since I got it 6 years ago (probably should read back through this thread to find out), and so might be due for a replacement.









The Maurice Lacroix is looking good this year, finally. Will have to see what 2017 brings.









The Certina looks good, as it always has.









And the Sinn UX is fairly consistent. In this test I didn't bother resetting the test after the fall time change, but overall the performance has been fairly consistent. Will need to ask Sinn to adjust at battery change time.








I'd like to do some custom charting, but today is not the day as the boss is mumbling already. I need a day when she goes shopping or whatever when I'm totally alone and undisturbed.


----------



## Sabresoft

*July 2017 Update*

Breitling Airwolf Raven - Projecting a not so great 16.5 SPY - Definitely looks like crystal aging.









ChristopherWard C70 Brooklands - Shooting off into the stratosphere, probably will see a dead battery soon a la Miros a few years back









Maurice Lacroix Miros - Projecting a respectable 5.2 SPY









Certina DS2 - Projecting a respectable 5.6 SPY









Sinn UX - Projecting a COSC Upper Limit 25.5 SPY


----------



## junlon

I wonder if there is more than the "weak battery" that caused the performance issue of Christopher Ward C70 Brooklands.
From the 2016 curve, it performed well with an almost flat curve at the second half of 2016. Seemed something happened at the beginning of 2017.



Sabresoft said:


> ChristopherWard C70 Brooklands - Shooting off into the stratosphere, probably will see a dead battery soon a la Miros a few years back
> 
> View attachment 12312578


----------



## Sabresoft

junlon said:


> I wonder if there is more than the "weak battery" that caused the performance issue of Christopher Ward C70 Brooklands.
> From the 2016 curve, it performed well with an almost flat curve at the second half of 2016. Seemed something happened at the beginning of 2017.
> 
> 
> 
> Sabresoft said:
> 
> 
> 
> ChristopherWard C70 Brooklands - Shooting off into the stratosphere, probably will see a dead battery soon a la Miros a few years back
> 
> View attachment 12312578
> 
> 
> 
> My Miros did something similar a few years back as it's battery died. They both run the same caliber, so I'm pretty sure that the same thing is happening here. In fact in the last day or so the Miros was gaining hours, not seconds.
Click to expand...


----------



## Sabresoft

*November 2017 Time Change Update

*Only 4 watches made it to this test. The ChristopherWard C70 Brookline's battery died sometime since the last test.

Here are the charts:








































The Certina DS2 Precidrive continues to show impressive performance. The Precidrive movements look to be better than their predecessors in terms of on spec performance. Will need to continue observing this one to see if crystal aging effects become apparent.

The Sinn UX is fairly consistent, if at the upper limits of COSC. Will need to get it adjusted when it goes back to Sinn in the next year or two for battery replacement.

The Miros is disappointing heading back to 10 SPY after a short period of great performance.

I'm sure that the ChristopherWard C70 Brooklands will resume its great performance once the battery is replaced.

And the Breitling Airwolf looks to be needing an adjustment in the near future.

The testing will continue for 3 of the watches (Breitling, Maurice Lacroix and Certina) till DST in March. I didn't bother restarting the test for the UX, and I have yet to get the battery replaced in the CW.


----------



## Sabresoft

*2018 DST Time Change Update*

This is probably the last test in my series here. Just not finding the time to do my testing. I have reset all my watches at this point and may do a 365 day check, but I won't be doing the periodic checks throughout the year.

Only 3 watches made it to the end this time. The CW C70 test was not restarted after battery replacement, and the Sinn UX test was not restarted after the fall time change (necessary because changing from DST to ST requires adjusting the hands).

*The Airwolf*









There definitely looks to be aging effects judging by the parallel, but upward shifting curves each year. Still at a current 13.87 SPY not too shabby, although I'd prefer less than 10.

*The Miros*








Showing a disappointing SPY of 18.32, especially after being close to zero last year. Because of 2 battery replacements and attempting adjustments a couple of times over the last seven years the charts are all over the map. Still not a bad watch.

*The DS2*








A very commendable SPY of 3.44. Performance has been great over the years. I didn't realize that I have had that watch as long as I have (it's my most recent acquisition). Speaks well of the newer generation of thermocompensated calibers. Still even this watch show a little aging creep.

It has been fun, but I find the testing regimen has become a chore rather than the fun it was in the early days.


----------



## Trias

Sabresoft said:


> *2018 DST Time Change Update*
> 
> This is probably the last test in my series here. Just not finding the time to do my testing. I have reset all my watches at this point and may do a 365 day check, but I won't be doing the periodic checks throughout the year.
> 
> Only 3 watches made it to the end this time. The CW C70 test was not restarted after battery replacement, and the Sinn UX test was not restarted after the fall time change (necessary because changing from DST to ST requires adjusting the hands).
> 
> *The Airwolf*
> 
> 
> 
> There definitely looks to be aging effects judging by the parallel, but upward shifting curves each year. Still at a current 13.87 SPY not too shabby, although I'd prefer less than 10.
> (...)
> 
> *The DS2*
> 
> 
> A very commendable SPY of 3.44. Performance has been great over the years. I didn't realize that I have had that watch as long as I have (it's my most recent acquisition). Speaks well of the newer generation of thermocompensated calibers. Still even this watch show a little aging creep.
> 
> It has been fun, but I find the testing regimen has become a chore rather than the fun it was in the early days.


Just a word to commend the dedication you put in your accuracy tracking works. I was browsing for information about the Lancers, and stumbled upon your topic. It's too bad that kind of test isn't more common, as it provided information about the behavior of the movements along the years (besides the just manufactured specifications we do have). I might include something like that in my future review. And as that post survived through the years with several months between each update, I thought it'd be worthy to risk a kudos for the effort.


----------



## Jtphoto

I have an accuracy question. I see a lot of people comparing their watches against Atomic clock apps on their phones or computers. Is there a more accurate way? 
I have 2 different Atomic clock apps but they are VERY inconsistent and neither is the time displayed on my phone. 

I do however have 5 Atomic watches, 2 citizens (one is the Skyhawk Black Eagle), 2 G Shocks (Mud Master and Sky Cockpit), and a ProTrek (Climber series), all 5 of which are in perfect sync with each other ALL the time. The apps are never in sync with these watches. In checking today the apps are almost 2 seconds slower then my atomic watches. 

Is there another way to track real time for watches. 


Sent from my iPhone using Tapatalk


----------



## Barbababa

Jtphoto said:


> I have an accuracy question. I see a lot of people comparing their watches against Atomic clock apps on their phones or computers. Is there a more accurate way?
> I have 2 different Atomic clock apps but they are VERY inconsistent and neither is the time displayed on my phone.
> 
> I do however have 5 Atomic watches, 2 citizens (one is the Skyhawk Black Eagle), 2 G Shocks (Mud Master and Sky Cockpit), and a ProTrek (Climber series), all 5 of which are in perfect sync with each other ALL the time. The apps are never in sync with these watches. In checking today the apps are almost 2 seconds slower then my atomic watches.
> 
> Is there another way to track real time for watches.
> 
> Sent from my iPhone using Tapatalk


That sounds pretty strange, what apps are you using? I have the app for G-shock BT, Clock wave, and the Watchville, but I usually look at my Seiko Astron when synchronizing others


----------



## gaijin

Jtphoto said:


> I have an accuracy question. I see a lot of people comparing their watches against Atomic clock apps on their phones or computers. Is there a more accurate way?
> I have 2 different Atomic clock apps but they are VERY inconsistent and neither is the time displayed on my phone.
> 
> I do however have 5 Atomic watches, 2 citizens (one is the Skyhawk Black Eagle), 2 G Shocks (Mud Master and Sky Cockpit), and a ProTrek (Climber series), all 5 of which are in perfect sync with each other ALL the time. The apps are never in sync with these watches. In checking today the apps are almost 2 seconds slower then my atomic watches.
> 
> Is there another way to track real time for watches.
> 
> Sent from my iPhone using Tapatalk


Sure! Buy and use one of these:

LeoNTP Specifications
LeoNTP Instruction Manual
Purchase here at Airspy

Then use the video recording method at 120 frames/sec or better.

HTH


----------



## Jtphoto

gaijin said:


> Sure! Buy and use one of these:
> 
> LeoNTP Specifications
> LeoNTP Instruction Manual
> Purchase here at Airspy
> 
> Then use the video recording method at 120 frames/sec or better.
> 
> HTH


So, where does this unit receive its time signal? EDIT from GPS Satellite which gets its signal From the Atomic Clock Towers and that is the time delay of what I speak. Same delay as phone apps. 
Has anyone compared their Atomic watch to one of these units?

Sent from my iPad using Tapatalk


----------



## gaijin

Jtphoto said:


> So, where does this unit receive its time signal? EDIT from GPS Satellite which gets its signal From the Atomic Clock Towers and that is the time delay of what I speak. Same delay as phone apps.
> Has anyone compared their Atomic watch to one of these units?
> 
> Sent from my iPad using Tapatalk


A direct GPS satellite reception on a dedicated time transfer receiver like the LeoNTP Stratum I Master Clock is <40 nanoseconds (Reference on GPS.gov here: GPS.gov - GPS Accuracy):

*How accurate is GPS for timing?*
_GPS time transfer is a common method for synchronizing clocks and networks to Coordinated Universal Time (UTC). The government distributes UTC as maintained by the U.S. Naval Observatory (USNO) via the GPS signal in space with a time transfer accuracy relative to UTC(USNO) of ≤40 nanoseconds (billionths of a second), 95% of the time. This performance standard assumes the use of a specialized time transfer receiver at a fixed location._

Phone Apps and "Atomic" watches I have measured using the LeoNTP reference can be off as much as a + a full second immediately after sync. When you say, "Same delay as phone apps" you are very wrong - there is no comparison.

HTH


----------



## Jtphoto

Are you sure it’s the watch’s that are off? Satellites get there time signal from the same atomic clock towers. 


Sent from my iPhone using Tapatalk


----------



## gaijin

Jtphoto said:


> Are you sure it's the watch's that are off? Satellites get there time signal from the same atomic clock towers.
> 
> Sent from my iPhone using Tapatalk


I suggest you read carefully the GPS.gov link I posted above. Yes. I am sure the Stratum 1 LeoNTP device is the more accurate time - by several orders of magnitude when compared to the watches. In fact, if you carefully read many of the Casio Owner's Manuals, you will find that they state quite clearly that immediately after syncing with an "Atomic" (really should be radio) signal, the displayed time could be off by as much as a second.

HTH


----------



## Jtphoto

I did and found this. 

Master time from a GPS

A common source of accurate time for a master clock is a global positioning satellite (GPS) signal. Satellites in space broadcast precise time all over the world. This time is received from the atomic clock, which is located at the National Institute of Standards and Technology or NIST in Colorado. The master clock in a school or business must have an antenna located outdoors in order to receive the GPS time signal and synchronize to it. The master clock communicates with the GPS every hour to acquire the correct time, which it passes along to the other clocks within the environment.

Still doing more research. 


Sent from my iPhone using Tapatalk


----------



## Jtphoto

Precise Time reference 

GNSS technologies have a design dependence on accurate timing. The resolution of positioning equations depend on the accurate timestamping of GNSS messages and the four variables resolved by positioning equations are: time plus the 3D position coordinates. Each navigation satellite has atomic clocks that are synchronized from a master clock on the ground and the navigation messages are timestamped with the transmission time of the signal.
This allows GNSS receivers to act as a worldwide synchronized time source with a precision that could only be maintained during long periods by expensive equipments. This enabled a wide set of applications that rely on GNSS synchronized precise time sources. These applications can range from network synchronization and optimization to encryption and digital signature of electronic data.


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## Jtphoto

gaijin said:


> many of the Casio Owner's Manuals, you will find that they state quite clearly that immediately after syncing with an "Atomic" (really should be radio) signal, the displayed time could be off by as much as a second.
> 
> HTH


That's interesting then that all 5 of my atomic watches sync together exactly, every day, and they are not all Casios.

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## Jtphoto

gaijin said:


> I suggest you read carefully the GPS.gov link
> HTH


And directly from the link you posted.

How accurate is GPS for timing?
GPS time transfer is a common method for synchronizing clocks and networks to Coordinated Universal Time (UTC). The government distributes UTC as maintained by the U.S. Naval Observatory (USNO) via the GPS signal in space with a time transfer accuracy relative to UTC(USNO) of ≤40 nanoseconds (billionths of a second), 95% of the time. This performance standard assumes the use of a specialized time transfer receiver at a fixed location.

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## gaijin

Jtphoto said:


> And directly from the link you posted.
> 
> How accurate is GPS for timing?
> GPS time transfer is a common method for synchronizing clocks and networks to Coordinated Universal Time (UTC). The government distributes UTC as maintained by the U.S. Naval Observatory (USNO) via the GPS signal in space with a time transfer accuracy relative to UTC(USNO) of ≤40 nanoseconds (billionths of a second), 95% of the time. This performance standard assumes the use of a specialized time transfer receiver at a fixed location.
> 
> Sent from my iPhone using Tapatalk


As long as we appear to be posting random quotes, here's another one for you [Emphasis mine]:

*Global Navigation Satellite Systems[edit]*
_The Global Positioning System (GPS) operated by the US Air Force Space Command provides very accurate timing and frequency signals. A GPS receiver works by measuring the relative time delay of signals from a minimum of four, but usually more, *GPS satellites, each of which has at least two onboard caesium and as many as two rubidium atomic clocks.* The relative times are mathematically transformed into three absolute spatial coordinates and one absolute time coordinate.[90] GPS Time (GPST) is a continuous time scale and theoretically accurate to about 14 ns.[91] However, most receivers lose accuracy in the interpretation of the signals and are only accurate to 100 ns.[92][93] The GPST is related to but differs from TAI (International Atomic Time) and UTC (Coordinated Universal Time). GPST remains at a constant offset with TAI (TAI - GPST = 19 seconds) and like TAI does not implement leap seconds. *Periodic corrections are performed to the on-board clocks in the satellites to keep them synchronized with ground clocks.[94][95] The GPS navigation message includes the difference between GPST and UTC.* As of July 2015, GPST is 17 seconds ahead of UTC because of the leap second added to UTC on 30 June 2015.[96][97] Receivers subtract this offset from GPS Time to calculate UTC and specific time zone values._

Good luck with your research.


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## Jtphoto

What I found is those on-board satellite atomic clocks connect with the ground tower (NIST Master Clock) for time sync/corrections, in one article it stating every hour. 


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## Jtphoto

https://tf.nist.gov/general/pdf/2429.pdf



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## Barbababa

Jtphoto said:


> https://tf.nist.gov/general/pdf/2429.pdf
> 
> 
> 
> Sent from my iPhone using Tapatalk


Are you just trying to collect posts or do you not know the difference between radio control tower and a GPS satelite?
A lot of posts saying nothing... Just for your own measure of a watch, it does not matter what you use as long as it´s consistent over time (it´s the watch you are measuring not the source). Like a recently sychronized G-shock RC or a GPS watch or any app that is concistent. And you have not yet mentioned what apps you are using... The most accurate _time_ is from GPS like @gaijin pointed out.


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## DaveM

Jtphoto said:


> https://tf.nist.gov/general/pdf/2429.pdf
> 
> 
> 
> Sent from my iPhone using Tapatalk


Thanks for that. I think that it gives an excellent insight into the accuracy that you can expect from a 'Radio atomic clock'.

*I use the UK 'MSF' transmitter.*
Like the USA one in the Michael Lombardi paper it sends the information using a one-minute main-tick followed by 'morse coded' date, hour and minute-numbers. It is very easy to use, and after decoding I am left with a variability of less than 1 ms on each tick. I use it to calibrate my 10Mhz OCXO master-clock.


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## Trias

Jtphoto said:


> I have an accuracy question. I see a lot of people comparing their watches against Atomic clock apps on their phones or computers. Is there a more accurate way?
> I have 2 different Atomic clock apps but they are VERY inconsistent and neither is the time displayed on my phone.
> 
> I do however have 5 Atomic watches, 2 citizens (one is the Skyhawk Black Eagle), 2 G Shocks (Mud Master and Sky Cockpit), and a ProTrek (Climber series), all 5 of which are in perfect sync with each other ALL the time. The apps are never in sync with these watches. In checking today the apps are almost 2 seconds slower then my atomic watches.


About « atomic clock » websites and apps, I would advice being defiant as some of them do not feature network delay correction, nor periodic refreshing, nor precise setting of the part of the second where time is refreshed. I've been using one of those featuring none of that for a long time before realizing it was off by a few seconds right off the bat, and could be off by as much as 30s in 10-30 minutes if not manually refreshed. So « atomic clock » based in itself is far from being a warranty of accuracy. Which is why some apps/sites are good, and others are in fact inaccurate ; explaining the offset with your radio synced watches.

Among the good ones :

Time. gov : the reference according to some WUS accuracy tracking threads.
Time. is : the one I do currently use personally. About the same accuracy than Time.gov (at 0.02 to 0.1s from atomic time, in practice ±0.02s from time.gov), but more adapted for other time zones than NA.

Not gonna express myself over apps nor GPS methods as it's been done by Gaijin already.


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