# Will the *REAL* Bulova Precisionist Accuracy Specs Please Stand Up! (Hint: It's not +/-10 sec/yr)



## jlind (Jan 16, 2017)

Frustration grew to the breaking point seeing continued +/-10 sec/yr being touted and parroted as the Bulova Precisionist accuracy specs on the Internet, when they quietly disappeared years ago and are nowhere to be found on Bulova's web site. Inquired directly with Bulova what their specs are for all five of their Precisionist movements.

_"*jlind to Bulova*_​_"Comment = I have been scouring your web site looking for the accuracy specifications on your Precisionist watch movements, notably the following: P102 P123 8136 8137 8138. I cannot find any accuracy specifications anywhere. What are the guaranteed accuracy specs for those movements? Seiko, Citizen, and every Swatch Group brand provides guaranteed accuracy specifications for their watches. Bulova does not? Does that mean whatever accuracy it has brand new out of the box is what I must live with, even if it's losing or gaining over a minute per day? What ARE your precise, exact accuracy specifications for these 262kHz movements?"_​
This was the response I just received [drum roll please]:

_"*Kimberly H (Bulova Consumer Support)*_​_Sep 17, 2020, 2:17 PM PDT_​​_Hello John,_​​_Thank you for your inquiry._​​_The Precisionist movements have an accuracy of +/- 5 seconds a month._​​_We hope this information is helpful._​​_Sincerely,_​_Kimberly_​_Customer Care"_​
*That's +/-60 sec./yr., not the +/-10 sec/yr. they advertised when the Precisionist and Accutron II were released.* Why? The WUS High Accuracy Quartz forum here took them to task over it when their measurements were showing accuracy drift over time. I believe one or more of them were finding as much as 40 sec/yr (don't remember gain or loss). Following are three ads from circa 2010 or so when the Precisionist and Accutron II were first released, all claiming 10 sec/yr. The Internet lives forever.


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## ava1ar (Aug 5, 2020)

I don't think anyone was able to confirm +-10 sec/year with real Bulova watch. This +-5 sec/month looks are on the larger side, and from my experience they behave closer to the quartz COSC movements. I am observing my Bulova 8136 (Accutron II) gained around 2.9 seconds last month and Bulova P102 (Precisionist) around 2.2 seconds. This is giving us ~35 and ~26 seconds/year accordingly, which I consider good enough and not that far from the COSC results (<=25.5 seconds/year).
I believe guaranteed +-10 seconds/year (or even +-5 seconds a year) can be achieved only by few brands (like Citizen, Seiko, Longines). Other HAQ are at best matches the COSC (all HAQ ETA movements).


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## jlind (Jan 16, 2017)

ava1ar said:


> I don't think anyone was able to confirm +-10 sec/year with real Bulova watch. This +-5 sec/month looks are on the larger side, and from my experience they behave closer to the quartz COSC movements. I am observing my Bulova 8136 (Accutron II) gained around 2.9 seconds last month and Bulova P102 (Precisionist) around 2.2 seconds. This is giving us ~35 and ~26 seconds/year accordingly, which I consider good enough and not that far from the COSC results (<=25.5 seconds/year).
> I believe guaranteed +-10 seconds/year (or even +-5 seconds a year) can be achieved only by few brands (like Citizen, Seiko, Longines). Other HAQ are at best matches the COSC (all HAQ ETA movements).


Having worked for a company that provided specs for the performance of its products, it's common practice to "guard band" the nominal 3rd sigma performance in the advertised and promised specs, to avoid problems with the infrequent outlier. In addition, if nominal performance variation is well within the advertised specs, customers tend to be happier.


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## ava1ar (Aug 5, 2020)

Interesting, if +-10 seconds/year was clear missinformation by Bulova on their ads, or they early produced watches were fitting this window? May be they got worse due to some simplifications or worth quality control and Bulova just silently removed any mention of the accuracy to match the real watches behavior?


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## odd_and_vintage_fan (Dec 4, 2014)

Anecdotally, my Moonwatch settled in from +12 per year to dead even per year over the life of the first battery. Drift at the end was +6 the first half of the year then -6 the second half or vice versa.

Still, this is just my data point and everyone's mileage seemed to have varied.

Edit: For all of the hoopla and ballyhoo about the accuracy at release, +\- 5 a month is somewhere between frustrating and depressing. I really wanted Bulova to do well.


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## gaijin (Oct 29, 2007)

Well... COSC Quartz specs are, actually, +/- 73.05 Sec/Year if one does not also specify the temperature range:










So... if all the Bulova rep said was "+/- 5 Seconds / Month" without specifying a temperature range, then that could very well be well within the COSC Quartz spec of +/- 73 Sec/Year.

Ergo... if COSC Certification (i.e. "Chronometer" on the dial) is all that's needed to be considered HAQ, then based on specs alone the Bulova still seems to be in the club.

HTH


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## jlind (Jan 16, 2017)

ava1ar said:


> Interesting, if +-10 seconds/year was clear missinformation by Bulova on their ads, or they early produced watches were fitting this window? May be they got worse due to some simplifications or worth quality control and Bulova just silently removed any mention of the accuracy to match the real watches behavior?


It's my belief they thought it was going to perform that well from the outset, perhaps overoptimistic expectations from design concept estimates (I've seen a few engineering organizations engage in self-feeding unrealistic optimism). If they didn't take into account actual electronic component value variation and their stackup in the circuitry, the actual results won't match the anticipated when it goes into production. In addition, if performance is hypersensitive to a particular component value and that isn't detected and mitigated, you'll also have much larger variation than was projected. I could go deeper into this, including some of the errors I've seen occur in circuit analyses, but it would require more than practical to present in a forum so that nearly all could qualitatively understand it (versus quantitative that requires advanced mathematics). The observed accuracy drift over time leads me to believe component aging (most likely suspect: quartz crystal) has a big hand in it.


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## tmathes (Jan 11, 2013)

Their specs were relaxed years ago in writing, I have a 3 year old Precisionist chronograph (the model was discontinued) with the 5sec/month number in the booklet. So, they did have it writing at one point.

Dump Certina in that same bucket as Bulova for "10 sec/year" being garbage; try 2-3x that for Certina in real models. My two Certina Precidrives (DS-2 chrono and DS-8 chrono) are more like +18 sec/yr (DS-8) and +26 sec/yr (DS-2). By the "10 sec/yr" metric Cerina/ETA Precidrive isn't HAQ either.


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## bombaywalla (Oct 8, 2011)

jlind said:


> It's my belief they thought it was going to perform that well from the outset, perhaps overoptimistic expectations from design concept estimates (I've seen a few engineering organizations engage in self-feeding unrealistic optimism). If they didn't take into account actual electronic component value variation and their stackup in the circuitry, the actual results won't match the anticipated when it goes into production. In addition, if performance is hypersensitive to a particular component value and that isn't detected and mitigated, you'll also have much larger variation than was projected. I could go deeper into this, including some of the errors I've seen occur in circuit analyses, but it would require more than practical to present in a forum so that nearly all could qualitatively understand it (versus quantitative that requires advanced mathematics). The observed accuracy drift over time leads me to believe component aging (most likely suspect: quartz crystal) has a big hand in it.


Darn, you burst my bubble! 😪😪
I just acquired a Bulova Lunar Pilot & was so happy it was a HAQ until i read this thread....
Still I'm going to keep some tabs on its performance to see if i can determine what it's actually doing.

If people are observing drift over time, I agree with you: it's likely component aging & even crystal aging.
There's a lot of info on crystal aging in RF electronics & one can borrow that info for quartz watches --> my understanding is that crystals age the most soon after manuf. like in the 1st 45 days & then settle down. So, a lot of the HAQ manuf age their cystals for months before casing the movement. The crystal will continue to age after that but if the manuf has ensured the drive level is low that helps to contain the aging. Also, if the user &/or Service Center do not fiddle with the encapsulated crystal then aging is also slowed down. I've seen crystal aging numbers like 5ppm --> if i did the math correctly that equates to 5 sec per 11.57 days which works out to 157.68 sec per year. That's quite a bit of aging for a HAQ watch. I'm sure that, besides the thermo-compensation circuitry, the controller IC also has a calibration algorithm on-IC to compensate for the crystal aging otherwise, just the crystal aging would gradually make a HAQ go out of spec! 😲

OTOH, if Bulova says their performance is +/- 5 sec/month right from the get-go then it must be component tolerance that is dictating the spec (assuming the crystal has been aged in the factory before casing).

In another post someone mentioned COSC quartz accuracy is less than 25 sec/year. When i visited the COSC website I saw +/-0.2 sec/day, which is +/- 6 sec/month, which is +/- 72 sec/year. did i read the specs incorrectly on the COSC website?


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## ava1ar (Aug 5, 2020)

bombaywalla said:


> In another post someone mentioned COSC quartz accuracy is less than 25 sec/year. When i visited the COSC website I saw +/-0.2 sec/day, which is +/- 6 sec/month, which is +/- 72 sec/year. did i read the specs incorrectly on the COSC website?


Are you reading this: Quartz movements | COSC










0.2 sec/day is a worth case, normally it is 0.07 sec/day, so here is where 25 secs are coming from.


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## bombaywalla (Oct 8, 2011)

ava1ar said:


> Are you reading this: Quartz movements | COSC
> 
> View attachment 15457054
> 
> ...


yup! I read it correctly but I remembered "wrong"!!  
You are correct - the +/- 0.07 works to +/- 25.2 sec/year.

The "wrong" in quotes because I was thinking the following - when we wear our watches over the course of hours the watch will take on our body temp which is closer to 38C (it is certainly not 23C). So, I noted the +/- 0.2 sec/day number & ditched the +/- 0.07 spd @ 23C number. 
Maybe this is the wrong thing to do ??

Does the manuf set the watch accuracy to 38C in the factory knowing that is the "ambient temp" for the watch when worn? That would mean very little power consumption by the electronics to maintain the crystal at 38C because it's already at 38C thanks to the body temp.
You could argue then when the watch is sitting in its case, the temp comp is working hard to keep the crystal working at 38C when the box temp is really 23C.

If the watch manuf calibrates the crystal to 23C then it's the opposite of the above. Either way there are pros & cons.

anyway, that's why the +/- 0.2 spd stuck in my head......
Not saying it's right but this was my reasoning.


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## ava1ar (Aug 5, 2020)

bombaywalla said:


> Not saying it's right but this was my reasoning.


We are talking here about the COSC certification measurements, not the real watches with real crystals behavior. In my understanding, the thermocompesation exist in HAQ movements exactly with the aim to reduce temperature fluctuations in the watch. So, probably thermocompesated movements are doing much better in real life than COSC demands for 8C and 38C. At the same time - fix me if I am wrong here - not only thermocompesated movements are passing the COSC for quartz. So, may be for these movements this 0.2 s/d makes sense, since they are affected by temperatures changes more.

All above is just from my (limited) understanding about HAQ. Hopefully someone with better knowledge can confirm or correct this.


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## dwalby (Jun 25, 2018)

FWIW I have an Accutron II and its running about 4-5 sec fast since I reset it for DST back in March, so its in the ballpark of 10 sec/year. I may be off a little though as I vaguely recall I may have hacked it for a couple seconds a few months ago to put it dead on again. Too old to remember things like that for sure. So worst case its within 20 sec/year.


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## gaijin (Oct 29, 2007)

ava1ar said:


> We are talking here about the COSC certification measurements, not the real watches with real crystals behavior. In my understanding, the thermocompesation exist in HAQ movements exactly with the aim to reduce temperature fluctuations in the watch. So, probably thermocompesated movements are doing much better in real life than COSC demands for 8C and 38C. At the same time - fix me if I am wrong here - not only thermocompesated movements are passing the COSC for quartz. So, may be for these movements this 0.2 s/d makes sense, since they are affected by temperatures changes more.
> 
> All above is just from my (limited) understanding about HAQ. Hopefully someone with better knowledge can confirm or correct this.


Only thermocompensated quartz movements can be certified by COSC. Additionally, the quartz oscillator must be "rigorously encapsulated" to protect it from the effects of humidity:

" To acquire the COSC label, a quartz instrument must benefit from thermo-compensation and rigorous encapsulation." [Found here: Quartz Movements | COSC]

HTH


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## bombaywalla (Oct 8, 2011)

While it's too early to tell, I've had the Bulova Lunar Pilot just 1 month & the accuracy it trending within the HAQ range


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## Tom-HK (Jan 6, 2015)

bombaywalla said:


> While it's too early to tell, I've had the Bulova Lunar Pilot just 1 month & the accuracy it trending within the HAQ range
> 
> View attachment 15479174


What am I missing? This result seems to say that your Bulova is currently performing well outside the 10 seconds per year figure that we throw around in these parts as the HAQ benchmark.


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## bombaywalla (Oct 8, 2011)

Tom-HK said:


> What am I missing? This result seems to say that your Bulova is currently performing well outside the 10 seconds per year figure that we throw around in these parts as the HAQ benchmark.


You have assumed that each month it will gain 1.7 sec/month. Can you be 100% sure of that?? - that for the next 11 months it will _always_ gain time? And, that same amount?


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## ugawino (Jan 20, 2019)

Look at the bright side. It's still way more accurate than a $5K Speedmaster or $10K Submariner.


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## ava1ar (Aug 5, 2020)

bombaywalla said:


> You have assumed that each month it will gain 1.7 sec/month. Can you be 100% sure of that?? - that for the next 11 months it will _always_ gain time? And, that same amount?


Yes, this is how watches tend to behave. The numbers may change a bit depending on usage pattern (you wear it more or less, temperature outside, etc), but this is how estimations are usually done to calculate SPY value.

Here is my Bulova Precisionist stats for last almost two months. You can see it gais aroud 0.063 seconds per day (at this is pretty consistent). So SPY is predicted to be 0.063*365 which is approximate 23 seconds. Not the best HAQ I have for sure, but within Quartz COSC, which is pretty good.


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## Tom-HK (Jan 6, 2015)

bombaywalla said:


> You have assumed that each month it will gain 1.7 sec/month. Can you be 100% sure of that?? - that for the next 11 months it will _always_ gain time? And, that same amount?


The way I was reading the result it seemed like 1.7 seconds per day.


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## bombaywalla (Oct 8, 2011)

Tom-HK said:


> The way I was reading the result it seemed like 1.7 seconds per day.


got it!!
  it's a quartz watch, maan!!
+1.7spd would mean it's a like a Rolex automatic, which would end up being 600-700 sec/year. That would worse that a 1970s $50 quartz - so, my Bulova would have been fit for the garbage bin!!
no, it was +1.7 sec over 1 month.
After reading Ava1ar's post, your comment about exceeding +/- 10 sec per year probably still holds as I am now made to understand that this trend of gaining time will continue......😪


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## ava1ar (Aug 5, 2020)

bombaywalla said:


> it was +1.7 sec over 1 month


This is not bad at all for the Bulova's HAQ. 10 SPY can be achieved only by some models/calibers and Bulova's 262kHz movement is definitely not in this group (even if some individual pieces can do that, this is just exceptions to prove the rule).


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## odd_and_vintage_fan (Dec 4, 2014)

Mine consistently gained differently between Summer and Winter and as the crystal aged and the battery voltage dropped. Just before the new battery, it was +6 over the cold months and -6 over the warm months, so 0 seconds per year. It's in a rotation, so it's typically at room temperature between 60 degrees F in the Winter and up to 90 degrees F in the Summer.

It got a new battery a few days after the last DST change, so I'll see what it's up to soon with full voltage.


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## jlind (Jan 16, 2017)

ava1ar said:


> I don't think anyone was able to confirm +-10 sec/year with real Bulova watch. This +-5 sec/month looks are on the larger side, and from my experience they behave closer to the quartz COSC movements. I am observing my Bulova 8136 (Accutron II) gained around 2.9 seconds last month and Bulova P102 (Precisionist) around 2.2 seconds. This is giving us ~35 and ~26 seconds/year accordingly, which I consider good enough and not that far from the COSC results (<=25.5 seconds/year).
> I believe guaranteed +-10 seconds/year (or even +-5 seconds a year) can be achieved only by few brands (like Citizen, Seiko, Longines). Other HAQ are at best matches the COSC (all HAQ ETA movements).


To clarify some facts about Bulova's 262kHz movements: There are five, and this was been verified with Bulova. Two use a 3V CR2016 Lithium and three use a 1.55V 395 Silver-Oxide:

P102.1x: 3-hand with date complication. Whether it's a Precisionist, Accutron II or "UHF", if it's a men's 3-hand + date, it's a P102.1x. Uses CR2016
P123: 4-eye 1/1000th second chronograph with 12 hour totalizer. 3rd pusher on left side switches between time and chrono modes. Uses CR2016
8136: 3-eye 1/20th second chronograph with 1 hour totalizer (the Lunar Pilot uses this one). This one was unquestionably derived directly from the Miyota 6S20. Uses 395
8137: 1/2 second chronograph with 12 hour totalizer. The seconds subdial is also the chrono seconds (no central seconds). Used in all the CURV chronographs.. Uses 395
8138: Women's 2-hand with a seconds sub-dial. Uses 395
I've seen photos of a P102.10 and P102.12, two revisions of the P102, similar to the "-2" revision ETA has used on its mechanical movements. All of mine are P102.12 revisions, in three Precisionist and two Accutron II.


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## James_ (Sep 5, 2011)

odd_and_vintage_fan said:


> Mine consistently gained differently between Summer and Winter and as the crystal aged and the battery voltage dropped. Just before the new battery, it was +6 over the cold months and -6 over the warm months, so 0 seconds per year. It's in a rotation, so it's typically at room temperature between 60 degrees F in the Winter and up to 90 degrees F in the Summer.
> 
> It got a new battery a few days after the last DST change, so I'll see what it's up to soon with full voltage.


Not 100% sure but I read years ago that if it's + sometimes then - other times, you put those together. So although yours works out dead on time after a year, that would be +/- 12spy.


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## jlind (Jan 16, 2017)

James_ said:


> Not 100% sure but I read years ago that if it's + sometimes then - other times, you put those together. So although yours works out dead on time after a year, that would be +/- 12spy.


You're missing the point . . . which is . . .
Bulova promised +/- 10 spy when the technology was introduced a decade ago. That promise mysteriously and very quietly disappeared. When pressed for it, their response is now +/- 60 spy, which is over a half an entire order of magnitude larger. *Bulova LIED to the consumer making false claims.* You may not find that disturbing, but I do. I find it very disturbing.

You may see performance balancing out over time with mechanical watches, as mechanical effects cause them to run fast and slow over time when they are worn. This has not been so with any of my quartz movements. NONE of them. This is wishful thinking with your head in the sand. I'm not getting anything close to +/- 10spy on any of four. They're proving out to be about +40 spy running fast, and that's being generous. They're all running very fast compared to the promised +/- 10spy. Room temperature isn't 60F in the Winter and 90F in the Summer. If that's your indoor room temperature variation, you're in serious need of HVAC work. "Room Temperature" is generally considered a near constant 72F year round.


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## Shark-sandwich (Mar 21, 2018)

Introducing The Precisionist X Collection, Celebrating 10 Years of Precisionist - Worn & Wound


We look at the new Bulova Precisionist X Collection, which brings three new watches to the family in celebration of its 10th anniversary.




wornandwound.com





There's a new one


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## James_ (Sep 5, 2011)

jlind said:


> You're missing the point . . . which is . . .
> Bulova promised +/- 10 spy when the technology was introduced a decade ago. That promise mysteriously and very quietly disappeared. When pressed for it, their response is now +/- 60 spy, which is over a half an entire order of magnitude larger. *Bulova LIED to the consumer making false claims.* You may not find that disturbing, but I do. I find it very disturbing.
> 
> You may see performance balancing out over time with mechanical watches, as mechanical effects cause them to run fast and slow over time when they are worn. This has not been so with any of my quartz movements. NONE of them. This is wishful thinking with your head in the sand. I'm not getting anything close to +/- 10spy on any of four. They're proving out to be about +40 spy running fast, and that's being generous. They're all running very fast compared to the promised +/- 10spy. Room temperature isn't 60F in the Winter and 90F in the Summer. If that's your indoor room temperature variation, you're in serious need of HVAC work. "Room Temperature" is generally considered a near constant 72F year round.


Not really bothered about what Bulova did or didn't say, it's old news. I'm attempting to address the point about overall accuracy and the way people present it.

Carry on.


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## James_ (Sep 5, 2011)

I will say though that all 6 Bulovas I've had in the past with the UHF movement have seemingly been within 10spy in the months I wore them.

2 Military UHF 3 hand 
2 Accutron II Alpha
1 Military Chronograph 
1 Moonwatch


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## Tom-HK (Jan 6, 2015)

jlind said:


> You may see performance balancing out over time with mechanical watches, as mechanical effects cause them to run fast and slow over time when they are worn. This has not been so with any of my quartz movements. NONE of them. This is wishful thinking with your head in the sand. I'm not getting anything close to +/- 10spy on any of four. They're proving out to be about +40 spy running fast, and that's being generous. They're all running very fast compared to the promised +/- 10spy. Room temperature isn't 60F in the Winter and 90F in the Summer. If that's your indoor room temperature variation, you're in serious need of HVAC work. "Room Temperature" is generally considered a near constant 72F year round.


Just to pick up on this point, quickly, I should say that you are more likely to see rates averaging out over time when you look at HAQs for a couple of reasons.

The first is quite simply that we deal with smaller changes and monitor those changes very closely. Or, at least, we used to. Go back in this forum a few years and have a look at all the day-by-day rate tracks that some of used to keep (and post). It is not at all unusual to see rates differ significantly* between summer and winter.

The second the reason, I believe, would be that 'ordinary' quartz watches have their rate fixed at or about the top of the temperature/rate bell curve. Regardless of whether the summer is hot or the winter is cold, the rate is likely to change by similar amounts. We have seen a different approach apparent in at least some of the HAQs we have tested over the years, with the nominal rate set somewhere near the top on the upward trending slope of the bell curve, so you would see a speed-up or a slow-down, depending on which way the weather trends. Possibly this is to make the count correction simpler to calculate and implement, I don't know, but it is one of those strange quirks which has been noticed in some HAQs that we have been able to test.

*The amount of change that we might consider 'significant' for a HAQ is really quite small and might be missed by less sensitive modes of analysis.


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## tomchicago (Feb 15, 2010)

All of my quartzes (mix of Seiko and Casio-- none are HAQ) achieve, at worst, +0.5/day. More typical is +0.125 to +0.25/day. The described performance from the ImPrecisionist is unacceptable.


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## Zedd88 (Sep 6, 2020)

Hmmm. Interesting topic as I own a Bulova Lunar Pilot. I am using the app Atomic Clock and Watch Accuracy to record my watches. And my Bulova Lunar Pilot has a 0.00 spd but I think the app just isn't capable of rounding it off.

My watch was -3 seconds behind in Oct 20, 2019 and on Sept 28, 2020 it was -5 seconds behind. So basically it has lost 2 seconds in a span of 11 months! 









But seeing the posts here I believe the watch is not thermo compensated. Since I live in a tropical country where the temperature throughout the whole year is almost the same maybe that's why I get the accuracy I am getting?

Or does this mean that my watch would start to degrade over the years. I've only had the watch for a year.

Anybody else getting the same accuracy? Who lives in a country that more or less have the same temperature the whole year?


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## bombaywalla (Oct 8, 2011)

tomchicago said:


> All of my quartzes (mix of Seiko and Casio-- none are HAQ) achieve, at worst, +0.5/day. More typical is +0.125 to +0.25/day. The described performance from the ImPrecisionist is unacceptable.


well, standard Quartz is +/- 0.5spd which amounts to +/- 180sec per year.
You are saying your regular non-thermo comp quartz give yout 1/2 to 1/4 the error -- That's good. Maybe luck of the draw?


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## tomchicago (Feb 15, 2010)

This is across nearly 30 such watches so if it's luck, it's extraordinarily lucky.



bombaywalla said:


> well, standard Quartz is +/- 0.5spd which amounts to +/- 180sec per year.
> You are saying your regular non-thermo comp quartz give yout 1/2 to 1/4 the error -- That's good. Maybe luck of the draw?


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## bombaywalla (Oct 8, 2011)

tomchicago said:


> This is across nearly 30 such watches so if it's luck, it's extraordinarily lucky.


Agree. If your results are across 30 some watches then it's hardly luck. Ive never measured the accuracy of my standard quartz so I can say but maybe standard quartz has improved ? Or, the manuf sandbag so the user cannot find a reason to return watches (I think this must be it)....


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## zilch0md (Jan 27, 2014)

Only two months in, my Bulova Langford is staying within 10 seconds per year, so far.










We will see if it can hold that accuracy.


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## Zedd88 (Sep 6, 2020)

My watch has still maintained it's accuracy of -2 seconds per year.










I admit, I haven't been religiously measuring it like before (when it was new - see my post above). But still I am impressed. Again, maybe it's just the weather I live in.


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## zilch0md (Jan 27, 2014)

I should have waited at least 60 days but, reading Zedd88's posts, I just had to know how my new Lunar Pilot "Archive" is doing. ?

Here's hoping it continues like this. I'm stoked. ?










For anyone unaware, the second hand of the Lunar Pilot is at the bottom subdial.


















Time Duration Calculator: Time between two dates/times


The Time Duration Calculator will calculate the time that has elapsed/difference between two dates with time.




www.timeanddate.com


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## Zedd88 (Sep 6, 2020)

zilch0md said:


> I should have waited at least 60 days but, reading Zedd88's posts, I just had to know how my new Lunar Pilot "Archive" is doing. ?
> 
> Here's hoping it continues like this. I'm stoked. ?
> 
> ...


That's pretty accurate and more or less on par with mines loosing -2 seconds per year. But I have seen others post the poor performance on their Bulova Lunar Pilot.

I hope our Bulova Lunar Pilot's accuracy last or don't degrade over time.


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## Barbababa (Jan 6, 2019)

jlind said:


> You're missing the point . . . which is . . .
> Bulova promised +/- 10 spy when the technology was introduced *a decade ago*. That promise mysteriously and very quietly disappeared. When pressed for it, their response is now +/- 60 spy, which is over a half an entire order of magnitude larger. *Bulova LIED to the consumer making false claims.* You may not find that disturbing, but I do. I find it very disturbing.
> 
> You may see performance balancing out over time with mechanical watches, as mechanical effects cause them to run fast and slow over time when they are worn. This has not been so with any of my quartz movements. NONE of them. This is wishful thinking with your head in the sand. I'm not getting anything close to +/- 10spy on any of four. They're proving out to be about +40 spy running fast, and that's being generous. They're all running very fast compared to the promised +/- 10spy. Room temperature isn't 60F in the Winter and 90F in the Summer. If that's your indoor room temperature variation, you're in serious need of HVAC work. "Room Temperature" is generally considered a near constant 72F year round.


I am to understand that this all comes down to that You think Bulova is making false claims?
As I read your conversation with Bulova, they don´t claim +/-10spy any more, and the ads you refere to are quite old (a decade?). If there is no recent claims from Bulova with the +/-10spy I cant see there is any blame on Bulova.
Maybe it´s more likely that the statement that Acutron is HAQ is something that just keeps living it´s own life, just like the 50 year service interval on GS 9f...
If the manufacturer makes new watches and don´t state the accuracy of the watch, it´s not the same as all old specs are transferred to the new. I would agree that Bulova should state the accuracy in the manual, and I understand why they leave it out in the ads if it´s only +/-5spm.
Conclusion = Modern Bulova is not HAQ


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## zilch0md (Jan 27, 2014)

What are the absolute minimum attributes or specifications that must be present to justify use of the acronym HAQ? Can we rule out COSC "Chronometer" certification?

This is an honest "noob" question. Thanks!


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## gaijin (Oct 29, 2007)

zilch0md said:


> What are the absolute minimum attributes or specifications that must be present to justify use of the acronym HAQ? Can we rule out COSC "Chronometer" certification?
> 
> This is an honest "noob" question. Thanks!


I humbly refer you to this thread: What is HAQ?

As far as COSC Certification being enough, no, it is not. COSC specs are +73sec/year (or thereabouts) where HAQ is aiming for +10 sec/year.

HTH


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## Barbababa (Jan 6, 2019)

zilch0md said:


> What are the absolute minimum attributes or specifications that must be present to justify use of the acronym HAQ? Can we rule out COSC "Chronometer" certification?
> 
> This is an honest "noob" question. Thanks!


I agree with @gaijin link, but as a quick tell, there must be thermocompensation making the performance controlled


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## zilch0md (Jan 27, 2014)

Reading @ronalddheld 's sticky ...









What the HAQ Forum Is (and Is Not) About - Please read...


Welcome to the High Accuracy Quartz forum! So, what the HAQ are we about? This is not a general Quartz forum. Our core interest is simple -- exceptional timekeeping. The purpose of a watch is to mark the passage of time, and we enjoy discussing quartz watches (and other types of "electro...




www.watchuseek.com





... the only requirement I see for declaring a watch to be HAQ is a measured offset less than 10 s/y based on measurements referencing atomic standards.

*Emphasis* is mine:



> The primary focus of the HAQ forum is intrinsic accuracy. A modern HAQ is a watch that who's offset is no worse than 10 s/y, based on measurements(referenced to atomic standards). A 32KHz movement almost certainly has a form of Digital Thermocompensation method. *A higher frequency movement may not, but still has to demonstrate it does not deviate by no more than +- 10 s/y. *Other side topics we have discussed are RC/BT/GPS watches, but they are not the primary topic. Ordinary Quartz movements are not a topic in this forum.


@gaijin quoted that sticky, but seems to have misinterpreted it as saying that HAQ also requires thermal compensation. Either that or he chose to add that requirement to the definition, on his own. (Note that I've not read his entire thread, yet.)

Entertaining the possibility that RonaldDHeld is wrong and Gaijin is right, is it safe to say that any watch, even though COSC Certification is not needed for HAQ designation, is worthy of the HAQ designation, if it can endure COSC test procedures (across multiple temperatures), yet have an offset less than 10 s/y (vs. COSC Certification's more relaxed 25.55 s/y)?

Or... would Gaijin say that it must not only demonstrate a 10 s/y insensitivity to temperatures defined by COSC testing, but must also possess some specific technology for thermal compensation?

What is the consensus of opinion, here?

I'm good with gaijin's definition of HAQ as long as he makes no demands on exactly how a timepiece manages to exhibit insensitivity to COSC-defined temperature extremes, albeit at the tighter offset of 10 s/y.

This topic seems to be a can of worms created by imprecise writing. And I am often guilty of fully qualifying my statements, too. I should probably be PMing RonaldDHeld and Gaijin...

Update: I just finished reading Gaijin's thread and really like the quote of @Tom-HK that he included in the following post. I can see that RonaldDHeld like's it, too, so perhaps Ronald should rewrite his sticky. 😋









What is HAQ? Is COSC "Certified Chronometer&quot...


Easy questions, right? Apparently not. Up front I want to be clear that I am not looking to argue with anyone about their opinions; I simply want to state my opinions, my reasons for them, and perhaps stimulate some discussion around them. In that spirit, lets begin. Our Mr. Moderator...




www.watchuseek.com


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## gaijin (Oct 29, 2007)

zilch0md said:


> @gaijin quoted that sticky, but seems to have misinterpreted it as saying that HAQ also requires thermal compensation. Either that or he chose to add that requirement to the definition, on his own. (Note that I've not read his entire thread, yet.)
> 
> Entertaining the possibility that RonaldDHeld is wrong and Gaijin is right, is it safe to say that any watch, even though COSC Certification is not needed for HAQ designation, is worthy of the HAQ designation, if it can endure COSC test procedures (across multiple temperatures), yet have an offset less than 10 s/y (vs. COSC Certification's more relaxed 25.55 s/y)?
> 
> Or... would Gaijin say that it must not only demonstrate a 10 s/y insensitivity to temperatures defined by COSC testing, but must also possess some specific technology for thermal compensation?


First, the COSC Quartz specs are not +25.55 sec/year - they are +73 sec/year from 8 DegC - 38 DegC.

My interpretation of HAQ is demonstrated performance should be +10 sec/year from 8 DegC - 38 DegC; using COSC test protocol if possible. Here is an example of my reporting to justify HAQ status for my Omega X-33:










I agree some of the comments about thermocompensation have been vague, but they are easily forgiven when one acknowledges that no quartz movement would be able to meet the +10sec/year spec without it. In fact, thermocompensation is a prerequisite for COSC certification, i.e. "To acquire the COSC label, a quartz instrument must benefit from thermo-compensation and rigorous encapsulation." (See full COSC Quartz Movement certification standards here: COSC Quartz Test Requirements)

Some have posited that a high frequency movement may be able to meet the HAQ target of +10 sec/year from 8 DegC - 38 DegC without thermocompensation, but I have yet to see any data supporting that argument. Further, said high frequency movement would be ineligible for COSC Certification because of its lack of thermocompensation.

Obviously, just about any quartz watch is capable of demonstrating +10sec/year precision IF KEPT AT THE IDEAL TEMPERATURE TO ELICIT THAT RATE, but that in no way bestows HAQ status on that watch. That is why I strongly suggest that ALL watches put forward in this forum as HAQ should have accompanying performance data that include not only Rate data, but temperature data as well.

HTH


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## zilch0md (Jan 27, 2014)

gaijin said:


> First, the COSC Quartz specs are not +25.55 sec/year - they are +73 sec/year from 8 DegC - 38 DegC.
> 
> My interpretation of HAQ is demonstrated performance should be +10 sec/year from 8 DegC - 38 DegC; using COSC test protocol if possible. Here is an example of my reporting to justify HAQ status for my Omega X-33:
> 
> ...


Thank you for your very interesting and well-written reply, HTH!

Do you have any information and/or opinion regarding the alleged (partial) immunity to temperature changes enjoyed by the 262 kHz, Bulova Precisionist series' three-pronged, torsionally resonating quartz reference?


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## DaveM (Aug 9, 2008)

gaijin said:


> First, the COSC Quartz specs are not +25.55 sec/year - they are +73 sec/year from 8 DegC - 38 DegC.
> 
> My interpretation of HAQ is demonstrated performance should be +10 sec/year from 8 DegC - 38 DegC; using COSC test protocol if possible. Here is an example of my reporting to justify HAQ status for my Omega X-33:
> 
> ...


I agree.
*Almost any quartz watch can achieve 10spy in a temperature-controlled chamber.*
The devil is in the detail !

*Here are 2 manufacturing procedures*
a) Expensive watch. Rated 5spy from 8 to 38C
Temperature-cycle each watch, measure its temperature-vs-rate curve and store the results in the watches memory.
This calibration should produce watches which are well within 5spy from 8 to 38C.

b) Affordable watch. Rated 5spy from 20 to 30C
Measure the rate of each watch at 25C and store the results in the watches memory.
This calibration should produce watches which are well within 5spy at 25C.
The watch IS thermo-compensated, but uses a 'standard' compensation-curve. Temperature-drift will depend upon how closely each xtal matches the standard.

*Watches should stay within specification over their warranty period, but their xtals will drift with time .*
Statistical quality-control is required, This will use a small numbers of watches removed from the production line.
*Here are 2 quality-control procedures*
a) Expensive watch. Rated 5spy from 8 to 38C. Temperature-vs-rate curves individually calibrated.
Test when new.

this test validates the production process, all watches should easily pass.
Require a very high consistency ( say 6 sigma).
Test every 6 months during the warranty period

these tests validate long-term xtal stability
Accept a lower consistency ( say 3 sigma), perhaps decreasing with age.

b) Affordable watch. Rated 5spy from 20 to 30C. Fixed temperature-vs-rate curve.
Test the 25C rate when new.

this test validates the production process, all watches should easily pass.
Require a very high consistency ( say 6 sigma).
Test the 20C to 30C rate when new.

this test checks variability of the xtal temperature-curve.
Accept a lower consistency ( say 3 sigma)
Test every 6 months during the warranty period

these tests validate long-term xtal stability
Accept an even lower consistency ( say 2 sigma) perhaps decreasing with age.

*It is getting a bit complicated*
It I want to choose the most accurate watch I need to know

Rated tolerance
Over what temperature range
What is the probability of the watch meeting its rated specification.

For this forum :-
-10spy without a temperature-range is a waste of time
-The good thing about the COSC specification is that it is simple and absolute.
Many watches manufactured to 5spy, 20C to 30C, 1 sigma may fail the COSC test !

*So I think that a good entry-barrier for this forum is COSC without the temperature-compensation requirement.*


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## gaijin (Oct 29, 2007)

zilch0md said:


> Thank you for your very interesting and well-written reply, HTH!
> 
> Do you have any information and/or opinion regarding the alleged (partial) immunity to temperature changes enjoyed by the 262 kHz, Bulova Precisionist series' three-pronged, torsionally resonating quartz reference?


You're welcome!

When the Precisionist line was first introduced, I bought one. This was back in 2011, so I still was learning about testing and measurement techniques. Measurements were taken with a stopwatch using Time.IS as my reference. I wore the watch during the day for 19 weeks and was very impressed with the results; but then I let the watch sit on my desk at room temperature and the results were far less impressive:










Off the wrist, at room temperature, the rate quickly fell outside the 10 sec/year performance window which Bulova was stating as the performance spec at the time.

Even without specific temperature readings available for this test, it was clear that there was a performance difference between on-the-wrist rate and room temperature rate - clearly a rate difference due to temperature. We can assume that my "room temperature" was around 70 DegF at the time of the test - certainly not as extreme as 8 DegC - 38 DegC - yet the watch quickly went out of spec.

So, my opinion about the Bulova 262kHz movement? Nice idea, may afford some degree of temperature insensitivity greater than a non-thermocompensated 32kHz movement, but certainly not up to HAQ requirements.

Probably important to note that there are currently many variations of the 262kHz movement offered by Bulova/Citizen. I don't know whether the performance has improved, but the fact that they stopped mentioning the +10 sec/year performance spec, and the fact I have seen no actual performance data at temperatures from 8 DegC - 38 DegC which demonstrate HAQ performance, my conclusion is it is NOT an HAQ movement.

Data are the key.

HTH


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## Barbababa (Jan 6, 2019)

@DaveM "*So I think that a good entry-barrier for this forum is COSC without the temperature-compensation requirement.* "
Except there is no COSC without thermocompensation, or do you mean if a regular quartz performs within COSC?


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## dwalby (Jun 25, 2018)

zilch0md said:


> Do you have any information and/or opinion regarding the alleged (partial) immunity to temperature changes enjoyed by the 262 kHz, Bulova Precisionist series' three-pronged, torsionally resonating quartz reference?


Its part of the nature of crystal oscillators to change frequency over temperature, not just watch frequency crystals, but all crystals. Its not likely that the Bulova crystal is equivalent to a TC crystal. I own one, and its off the wrist most of the time and doesn't seem to be keeping 10spy accuracy under casual observation. The TCXO (temperature compensated crystal oscillator) is a commonly used part for clock generation in all types of electronic devices, not just watches, when accuracy and stability over temperature is desired.


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## jkpa (Feb 8, 2014)

When I had mine, both were within 10 spy. Cheapest way to get such incredible accuracy without atomic.


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## gaijin (Oct 29, 2007)

jkpa said:


> When I had mine, both were within 10 spy. Cheapest way to get such incredible accuracy without atomic.


Do you have any temperature and rate data over time to support that statement? (Asking for a friend )


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## jkpa (Feb 8, 2014)

gaijin said:


> Do you have any temperature and rate data over time to support that statement? (Asking for a friend )


😂 nope. Just checking vs Time.Gov every so often.


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## dwalby (Jun 25, 2018)

even with a TXCO typical accuracy of the crystal itself is in the range of 3-10ppm, which is an order of magnitude higher than the 0.3ppm required for +/-10 seconds per year divided by (60*60*24*365) seconds per year. So, do the watch makers add additional temperature characterization curves in software to make up that last order of magnitude? Or are there 0.3ppm or better TXCOs available in a form factor that would fit inside a watch case along with everything else needed for the movement/display?


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## DaveM (Aug 9, 2008)

Barbababa said:


> @DaveM "*So I think that a good entry-barrier for this forum is COSC without the temperature-compensation requirement.* "
> Except there is no COSC without thermocompensation, or do you mean if a regular quartz performs within COSC?


I mean that if a watch passes the COSC *tests* I think that it is good enough to appear in this forum.
Even with a High-frequency xtal it is unlikely that a watch will pass the COSC tests without thermo-compensation, but using thermo-compensation should not be a requirement.
A 'regular quartz' worn all of the time might easily improve on 10spy, it would not ( standard 32Khz tuning-fork xtal) perform within COSC !


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## gaijin (Oct 29, 2007)

DaveM said:


> I mean that if a watch passes the COSC *tests* I think that it is good enough to appear in this forum.


Are you saying that +73 sec/year @ 8 DegC - 38 DegC (COSC spec) is HAQ?

If so, I could not disagree more.


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## woodville63 (Dec 28, 2011)

I've got a 96B128 that needs a new battery. I'm embarrassed to say I can't get the battery to stay in place as it keeps popping out. Will see what Citizen Australia says, but I suspect it won't be worth getting fixed.


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## Barbababa (Jan 6, 2019)

DaveM said:


> I mean that if a watch passes the COSC *tests* I think that it is good enough to appear in this forum.
> Even with a High-frequency xtal it is unlikely that a watch will pass the COSC tests without thermo-compensation, but using* thermo-compensation should not be a requirement.*
> A 'regular quartz' worn all of the time might easily improve on 10spy, it would not ( standard 32Khz tuning-fork xtal) perform within COSC !


Well, like I said, no COSC certification without thermo-compensation according to COSC rules... It´s a package deal, .spy being a result of effeorts made to get there.
*Why do you feel the need to include watches that performs well that is not thermo-compensated?* Why would the quite small niche that is HAQ need to be extended?
When talking COSC in mechanical watches, there is basicly down to adjusting the watch in different positions, and that can be done without COSC certification by any watchmaker (or user with know-how). That´s not the case with quartz.
I would like to have a quartz forum where high end and well performing quartz was discussed too, but that does not mean I think it needs to be in the HAQ forum.


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## DaveM (Aug 9, 2008)

gaijin said:


> Are you saying that +73 sec/year @ 8 DegC - 38 DegC (COSC spec) is HAQ?
> 
> If so, I could not disagree more.


Are you saying that only better than 10 sec/year from *8 to 38C* is HAQ ?
If so only a few top end Japanese watches are HAQ
My main point is that defining HAQ in spy without a temperature range is a waste of time !


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## gaijin (Oct 29, 2007)

DaveM said:


> Are you saying that only better than 10 sec/year from *8 to 38C* is HAQ ?
> If so only a few top end Japanese watches are HAQ
> My main point is that defining HAQ in spy without a temperature range is a waste of time !


I am saying that HAQ should be *demonstrated performance* of +10 sec/year from 8 DegC - 38 DegC. Performance can be measured using the COSC Quartz testing protocol which is a 13-day test.

I have already well documented the HAQ status of my Omega X-33 Gen 2 - certainly not a "top end Japanese watch," but HAQ nonetheless.

And I agree, "...defining HAQ in spy without a temperature range is a waste of time !"

No data, no HAQ status - irrespective of any manufacturer specifications which may suggest the contrary.

HTH


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## DaveM (Aug 9, 2008)

gaijin said:


> I am saying that HAQ should be *demonstrated performance* of +10 sec/year from 8 DegC - 38 DegC. Performance can be measured using the COSC Quartz testing protocol which is a 13-day test.
> 
> I have already well documented the HAQ status of my Omega X-33 Gen 2 - certainly not a "top end Japanese watch," but HAQ nonetheless.
> 
> ...


*Yes, I agree almost 100% --*
No data, no HAQ status - irrespective of any manufacturer specifications which may suggest the contrary.

I agree with 10spy

My only problem is 8 to 38C, I think that it is too big a range.
Your X33 passed, but it is an expensive watch !
I have 2 Longines latest VHP
They are spot-on at wrist-temperature, but over 8 to 38C they are only just within COSC.
I think that this is because (to save money) they do not measure the temperature-curve of each watch.
They calibrate the 25C rate, but not the temperature-curve.
But to be fair they are sold at less than 50% of the Chronomaster price.

I think that because 99% of HAQ watches spend their off-wrist time in an air-conditioned room something like 

10spy
8 to 38C ambient when 'on the wrist'
15 to 30C ambient 'off the wrist
would ensure that 99% of watches achieved better than 10spy when in use.

My best mechanical watch ( Glashutte Excellence ) came with full details of its rate-test results.
Perhaps the Citizen 010 ( in view of its cost ) should be supplied with this data ?


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## gaijin (Oct 29, 2007)

DaveM said:


> I have 2 Longines latest VHP
> They are spot-on at wrist-temperature, but over 8 to 38C they are only just within COSC.


Then they are not HAQ.

I can easily see quartz watches being easily divided into three groups based on the results of the COSC Quartz testing protocol (8 - 38 DegC at 3 temps (8, 23, 38 DegC) over 13 days):

*Group 3*: Does not meet COSC Quartz standard, i.e. >+73 Sec/Year. This group could be referred to as "ordinary" quality quartz movements - not HAQ.

*Group 2*: Meets COSC Quartz standard, but is >+10 Sec/Year. This group could be referred to as "chronometer" quality quartz movements - but still not HAQ.

*Group 1*: Meets COSC Quartz standard, and is within +10 Sec/Year. This group could be referred to as "HAQ" quality quartz movements - definitely HAQ.

The key to all of this is data. Anyone is free to apply the COSC Quartz test protocol to ANY watch. If a movement has the theoretical technical capability to "test into" Group 1, then by all means test it!

The fascinating aspect of this HAQ forum for me is that one can not simply buy a watch that might be HAQ and claim HAQ status for that watch; but rather must submit that watch to a recognized test protocol and demonstrate performance to Group 1 HAQ standards.

This forum should not be just another WRUW forum where a picture of any "COSC," "Chronometer," "Chronometre," "Chronomaster," Grand Seiko," etc. watch is posted and represented as HAQ - without the test data to back it up, no such HAQ status can be claimed. There should be no automatic acceptance of any watch as HAQ without the appropriate supporting data.

I would thoroughly enjoy the posting by other members of their test results - HAQ or otherwise - with ensuing discussions about how to adjust the movement (if possible) to meet HAQ standards, details of measurement techniques and their various merits or pitfalls, temperature/rate curves, etc.

That would be so much more rewarding than, "Hey! Look at my neat watch!" posts - there are many other forums on WUS to support those.

HTH


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## zilch0md (Jan 27, 2014)

I've learned a lot from this thread and those referenced within, and I realize that the temperatures I'm about to share are basically worthless at predicting what others might be able to expect from my two Bulova Precisionists, given that I've not exercised all of the diligence required to take measurements that are universally meaningful, but...

Thanks to the fact that I work from home, as many do, and the fact that I have min/max recording digital thermometers upstairs and down, as well as a reliable history of outdoor min/max temperatures...

I can say, tongue-in-cheek, of course, that even though I've not performed _proper_ temperature-controlled testing, my Bulova Lunar Pilot is holding steady at -2 s/y and my Bulova Langford is staying within + 9 s/y, under the following minimums and maximums of temperature, for a period exceeding two months, and counting:

Indoor extremes: 72F to 85F (22.2C to 29.4C)
Outdoor extremes: 72F to 101F (22.2C to 38.3C)

My home office is upstairs, where I keep the thermostat at 84F (28.9C) (because I'm very frugal). 

I wear the Langford, but I've never worn the Lunar Pilot, which stays upstairs, with the temp never falling below 75F (23.9C) at dawn.

The Langford pretty much stays on my wrist, occaisonally experiencing outdoor temps, with shopping trips and daily walks, etc. - thus the extremes I've listed above and cooler temperatures it can experience downstairs, where my wife thinks money grows on trees. 

So, all of that must seem fairly worthless and difficult to assess, compared to the test protocols I have not followed, but it leads me to making this statement, with great confidence:

YMMV, of course, but I'm wearing a $148 watch that's staying inside of 10 s/y, thus far, across 2+ months of ownership during summer months - suffering my habits / my lifestyle, if you will.

That translates to my being very pleased with both of the Bulovas, even though they could both prove to be unworthy of even COSC certification, much less the more stringent (but elusive) HAQ designation.

In short, my ignorance of their true capability/incapability is nevertheless bliss, because they're performing wonderfully from where I sit (quite literally). 

Please forgive these ramblings of a poor man (relatively speaking), as I attempt to summon some appreciation for the lowly Bulova Precisionsts.


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## gangrel (Jun 25, 2015)

gaijin said:


> Are you saying that +73 sec/year @ 8 DegC - 38 DegC (COSC spec) is HAQ?
> 
> If so, I could not disagree more.


Does your watch ever get exposed to 8 degrees C for more than a few moments? Mine never have; I don't slip it into an outer pocket while winter hiking.

So this argument is a straw man.

Demonstrated performance is BS. We REGULARLY dismiss posters here who post about their basic quartzes doing so well, they're 2 seconds off in 8 months...because it's a sample size of 1, and the "test conditions" are unknown. The results do not translate reliably.

And demonstrated at extreme, totally unrealistic conditions is patently absurd when the watch is not going to be exposed to those conditions for extended periods. Could the 73 SPY be tighter? Probably, yes. The COSC quartz standard is guided by, I'd say, a more practical notion that "I can rely on the time shown on my watch during my day-to-day activities" and you're demanding something much closer to ivory-tower perfection.

This 'debate' is old and tired and we've regurgitated it TOO MANY TIMES.

Hey, if we want an engineering-analysis group that's all about finding the perfect movement...fine. The 99% of people who want to find out about a watch with practical accuracy, better than standard quartz, will continue to try...and continue to go, wow, the people in there are jerks!

Personally? Yeah, I know no one wants to do this, but I'd MUCH rather see this group expanded to include GPS and RF, and embrace that "chronometer" means "highly accurate." There is a formal, internationally accepted definition for what that means: ISO 3159. Was the choice of 10 SPY for this group anything more than caprice, at the time the group was conceptualized? Or a matter of "well these are the examples we have, and they're 10 SPY...so that's a good number!" At the time, fine...but it's being treated as Holy Writ, while the market has changed.

At the same time...fine, create an "engineering analysis" subforum. It probably won't get 10 posts a month.

The dissonance and rancor that recur _regularly_ have gutted this forum and caused QUITE a few of the regulars from 3-4 years ago to leave.


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## zilch0md (Jan 27, 2014)

@gangrel

We pretty much posted at the same instant and are saying much the same thing, one of us with a little more vigor and experience than the other.

I agree, even though I am ignorant of the apparent history of controvesy over this topic.

As an engineer, I can appreciate where both camps are coming from, so maybe thread titles should include "Engineers beware" or something like that.


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## zilch0md (Jan 27, 2014)

Three-month update...


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## zilch0md (Jan 27, 2014)

zilch0md said:


> Three-month update...
> 
> View attachment 16100273
> 
> ...


Not mentioned previously in this thread is that I have a 2nd Bulova Langford, for which I have just today done new calculations:









My Bulova Lunar Pilot was mentioned in a previous post. Here are its numbers, as of today:










So, three months in, my 2nd Bulova Langford (96B158) is leading the three Precisionists, with an interpolated offset of -1.3434 seconds per year.

The Lunar Pilot (96B251) is in the middle, three months in, with an interpolated offset of +4.9160 seconds per year.

My 1st Bulova Labgford (96B158) is at the rear of the pack, three months in, with a still respectable, interpolated offset of +10.1411 seconds per year.


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## zilch0md (Jan 27, 2014)




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## DCLion (Feb 20, 2016)

gaijin said:


> I humbly refer you to this thread: What is HAQ?
> 
> As far as COSC Certification being enough, no, it is not. COSC specs are +73sec/year (or thereabouts) where HAQ is aiming for +10 sec/year.
> 
> HTH


I believe COSC standards are .02 per day which is 7.3 per year, not 73.


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## DaveM (Aug 9, 2008)

DCLion said:


> I believe COSC standards are .02 per day which is 7.3 per year, not 73.


I just snipped this from the COSC web-site :-








At 25 seconds per year the 23C rate seems very generous
Especially as this is too short a test to check for ageing problems !

The 8 and 38C rates of 73 seconds per year are not as easy as they seem.
+/- 15C from the 'sweet spot' gives about +/- 250 seconds per year for a standard non-compensated watch.
So, as COSC say, you need thermal compensation or ( perhaps) a high-frequency xtal to meet the spec.
At less extreme range of +/- 10C halves the thermal drift.


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## gaijin (Oct 29, 2007)

DCLion said:


> I believe COSC standards are .02 per day which is 7.3 per year, not 73.


Your belief is wrong. COSC spec at upper and lower test temps is +0.20 sec/day which is +73 sec/year.

Even at a constant 23 DegC the COSC spec is +0.07 sec/day which is +25.6 sec/year.

Well outside the HAQ target of +10 sec/year.

HTH


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## DCLion (Feb 20, 2016)

gaijin said:


> Your belief is wrong. COSC spec at upper and lower test temps is +0.20 sec/day which is +73 sec/year.
> 
> Even at a constant 23 DegC the COSC spec is +0.07 sec/day which is +25.6 sec/year.
> 
> ...


You're right. I was looking at a website that was wrong.


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## ronalddheld (May 5, 2005)

No real harm done.


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## DCLion (Feb 20, 2016)

I have a question for this very knowledgeable forum. I recently got a 96B257 (I know it's not the most accurate watch in the world but really liked it's looks). Anyway, I've been checking it's accuracy with my iPhone Atomic Clock app. Yesterday, I checked it and it seemed to be about a half second fast. Today, it's exactly a week old and checked it and it was dead on at every marker. Just checked it now and it's about half a second fast again. Can someone help me understand the inconsistency? Why a different result at different times using the app?


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## ronalddheld (May 5, 2005)

Which atomic clock app did you use, and what was the offset between your iPhone time and reference time?


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## DCLion (Feb 20, 2016)

ronalddheld said:


> Which atomic clock app did you use, and what was the offset between your iPhone time and reference time?


 If you mean the delta between the atomic time from the app and the iPhone time, I think the iPhone time is about a second behind the atomic time.


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## jmnav (May 18, 2019)

ava1ar said:


> Interesting, if +-10 seconds/year was clear missinformation by Bulova on their ads, or they early produced watches were fitting this window? May be they got worse due to some simplifications or worth quality control and Bulova just silently removed any mention of the accuracy to match the real watches behavior?


I think you had your answer just above from @jlind. _Any_ precision claim is either true or false depending on what you mean and what you are accepting to do with your outliers.

_"10 sec/year"_ means *nothing*. Wait! _"60 sec/year"_ means *nothing* *either*. _ "99% will be under 60 sec/year"_ means something. But then, _"75% will be within 10 sec/year"_ means something too.

So it might happen that early watches were advertised _"10 sec/year*¹"_ and, upon seeing marketing results, the exactly same watches, with exactly same tolerances became "_60 sec/year*²"_ _._

Anyone can claim their quartz watches will be +-1s/month... it's only a matter of accepting returns for the 99% that won't make it and exchange them under warranty till their s*** sticks in the wall.

_---_
1. 75% of our watches will be no worse than 10 sec/year.
2. 95% of our watches will be 60 sec/year or better.


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## zilch0md (Jan 27, 2014)

My first of two Bulova Langford 96B158 (purchased new for $148) is magically running only 3.5 seconds slow after an 8-month, 11-day stretch (since June 2, 2021).


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## DCLion (Feb 20, 2016)

Just thought I'd give you guys an accuracy update. I've had my 96B257 a little over 3 weeks now. It looks like it gained exactly 1 second at the 3 week mark--about 17 sec per year. Not 10, but much better than any Rolex or Grand Seiko.


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## Le Estrada (Apr 24, 2021)

There are many ETA HAQ movements capable of 10 seconds per year. Precidrives give that performance. Longines VHP, especially tuned, is a variation of a Precidrive and gives 5 seconds per year. Anyway, also Omegas tool quartz watches give 10 seconds per year, X-33 and Z-33.


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## skspectre (Feb 22, 2015)

My Bulova Precisionist gains about 10 seconds a month on average, still pretty good since I'm not diffusing bombs or anything as time-critical.


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## zilch0md (Jan 27, 2014)

My first of two Bulova Langford 96B158 (purchased new for $148) is still running less than 4 seconds slow after 10-months (since June 2, 2021).


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## DaveM (Aug 9, 2008)

zilch0md said:


> My first of two Bulova Langford 96B158 (purchased new for $148) is still running less than 4 seconds slow after 10-months (since June 2, 2021).


*Can you give us some idea of the temperatures experienced by the watch?*
If 100% 'On the wrist'
++ 4 seconds in 10 months would indicate good initial calibration
If 100% 'Off the wrist' in an unheated house in Chicago
+++ 4 seconds in 10 months would be amazing !


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## DCLion (Feb 20, 2016)

And my 96b257 which has been on my wrist 95% of the time is running about 15 second fast a year.


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## zilch0md (Jan 27, 2014)

DaveM said:


> *Can you give us some idea of the temperatures experienced by the watch?*
> If 100% 'On the wrist'
> ++ 4 seconds in 10 months would indicate good initial calibration
> If 100% 'Off the wrist' in an unheated house in Chicago
> +++ 4 seconds in 10 months would be amazing !


Hi Ronald,

With very rare exceptions, I wear it indoors (where I tele-commute). The indoor temperature seldom ventures outside a range of 66F (winter months) to 75F (summer months), but my Min/Max thermometer reports these indoor figures: 66F to 85F (22.2C to 29.4C)

I take the watch off to shower and when sleeping.

I haven't recently checked or made reports on the accuracy of my two other Precisionists (another Langford and a Lunar Pilot), in part because I don't wear them, but I intend to report their one-year performance, anyway, this June.

Without question, it's a roll of the dice with the Bulova Precisionists, as to whether you will enjoy a sub 10-sec. offset across an entire year, given the variability coming from the manufacturer AND conditions of use, but I am nevertheless very impressed with all three of my Precisionists. 

Keep in mind that I would define myself as a fan of accuracy-on-the-cheap, where the money I've spent for each of three Citizen radio-controlled watches and a similar Seiko offering is right at the limit of my budget. A genuine COSC Chronometer, even with quartz movement, is out of reach. 

*Unlike my four radio-controlled Citizen and Seiko watches, whose accuracy I relish, despite the fact that some purists would say they are "cheating," I enjoy a unique satisfaction in observing and acknowledging that my relatively cheap Bulova Precsionists can perform so well with complete autonomy. With no external input, they substantially outperform most quartz watches, even some that are much more expensive (for features with which the Bulovas cannot compete).*

Take this with a grain of salt, but from the reseach I've done, the Bulova Langford's P102 (8-jewel, three-hand movement from 2010) is generally agreed to be more accurate than the later movements found in Precisionists that have either the 1/1000th or 1/10th-sec chronometer function. But that might just be anecdotal and echoed by others, as I am doing. 😋 I don't know of anyone who has purchased 10 of each and worn them all day, every day for a year. 😋 

Info about the P102, as seen in the Langford 96B158:



https://calibercorner.com/bulova-caliber-p102/


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## zilch0md (Jan 27, 2014)

I overshot my intended 365-day photo comparison by 1 day, 11 hours, 14 minutes and 45 seconds, but here is, what for me at least, the long-awaited result of a one-year test of my $148 Bulova 96B158.

+4.4 secs across 366d 11h 14m 45s.  



















I will soon be reporting the results of one year tests on a second 96B158 (never worn) and a 96B251 Lunar Pilot (never worn). Last I checked, they weren't doing quite as well. I'm afraid to look. LOL 

As I've stated before, I believe every Bulova Precisionist is a roll of the dice, not a guarantee of sub-ten-second accuracy, but for the money, they are remarkable. 

Mike


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## zilch0md (Jan 27, 2014)

I'll add that a friend has pointed out that this particular Bulova's error of only 0.00000137864% is equivalent to a measurement error of only...

137.864 microns (138/1000ths of a millimeter) over a distance of 1 kilometer...

or 221.870 microns over a distance of a mile... 

or 1.0 mm over a distance of 4.477 miles.

🥳


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## zilch0md (Jan 27, 2014)

Wanting to wrap this up, my other two Precisionist "tests" were close enough to having gone one year, I think it's safe to extrapolate the precision across 365 days.

Here you go:


















And the one I posted above, repeated here:










Talk about YMMV! MMMV! LOL

It's a roll-of-the-dice, but the Lunar Pilot and the 2nd Langford were never worn, where the first Langford has been worn daily. Who knows why one is blisteringly accurate and the other loses more than 5 secs per month? Poor QC? A few lemons get shipped? If I had the money, I would love to buy 10 of them and calculate a standard deviation. Oh well. 

Still, it seems chances are good that you could buy one or two, test them, sell the freak and buy another, then repeat until you've got a good one.

The Lunar Pilot uses a different caliber (obviously), so we can't really compare it to the Langfords, but at least it stayed within the touted +/-10 s per year (not worn).

The End

Ahhhhh...

Mike


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## jcp123 (Feb 4, 2012)

I have an older Claremont with that weird curved crystal/bezel thing, inherited from my Pa when he passed in January. He sure gave this thing a good beating for having worn it for less time that I wore my Citizen, and it shows.I just started giving a crap about how accurate it is. Took my first measurement on Toolwatch…waited like three weeks, since these want to play the long game. +.3spd. Nice but nowhere near the original claims, lol. Still, that makes it a good watch in my book.


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## ronalddheld (May 5, 2005)

jcp123 said:


> I have an older Claremont with that weird curved crystal/bezel thing, inherited from my Pa when he passed in January. He sure gave this thing a good beating for having worn it for less time that I wore my Citizen, and it shows.I just started giving a crap about how accurate it is. Took my first measurement on Toolwatch…waited like three weeks, since these want to play the long game. +.3spd. Nice but nowhere near the original claims, lol. Still, that makes it a good watch in my book.


A watch running 3 s/d does not belong here.


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## jcp123 (Feb 4, 2012)

ronalddheld said:


> A watch running 3 s/d does not belong here.


.3

Not 3.


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## ronalddheld (May 5, 2005)

Maybe stop buying HAQ watches in lieu of new glasses?
Still out of HAQ Territory.


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## jcp123 (Feb 4, 2012)

ronalddheld said:


> Maybe stop buying HAQ watches in lieu of new glasses?
> Still out of HAQ Territory.


Perhaps you need to read my post a bit more carefully? Buying wasn’t mentioned either.


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## Doninvt (Oct 5, 2018)

Not a Bulova, but just to throw in the mix, mostly off wrist:


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## DCLion (Feb 20, 2016)

jlind said:


> Frustration grew to the breaking point seeing continued +/-10 sec/yr being touted and parroted as the Bulova Precisionist accuracy specs on the Internet, when they quietly disappeared years ago and are nowhere to be found on Bulova's web site. Inquired directly with Bulova what their specs are for all five of their Precisionist movements.
> 
> _"*jlind to Bulova*_​_"Comment = I have been scouring your web site looking for the accuracy specifications on your Precisionist watch movements, notably the following: P102 P123 8136 8137 8138. I cannot find any accuracy specifications anywhere. What are the guaranteed accuracy specs for those movements? Seiko, Citizen, and every Swatch Group brand provides guaranteed accuracy specifications for their watches. Bulova does not? Does that mean whatever accuracy it has brand new out of the box is what I must live with, even if it's losing or gaining over a minute per day? What ARE your precise, exact accuracy specifications for these 262kHz movements?"_​
> This was the response I just received [drum roll please]:
> ...


I had/have two of them (gave one to my son-in-law)--the 96B158 was accurate to around 10 seconds/year. The one I currently wear (96B257) is accurate to about 15 seconds/year--both of these are an order of magnitude more accurate than most other quartz watches.


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## gaijin (Oct 29, 2007)

Doninvt said:


> Not a Bulova, but just to throw in the mix, mostly off wrist:
> View attachment 16982331


Sorry, but not even anywhere near the mix:

*ACCURACY*
_Seiko claims that the caliber 7T62 will maintain accuracy of +/- 15 seconds per month at normal operating temperatures of about 41F to 95F. The alarm is accurate to +/- 1 minute._

Credit: Caliber Corner © 2022, All Rights Reserved. Source: https://calibercorner.com/seiko-caliber-7t62/ .

And directly from Seiko: SEIKO_7T62.pdf

Most definitely NOT HAQ.

HTH


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## fmc000 (Nov 24, 2011)

gaijin said:


> Sorry, but not even anywhere near the mix:
> 
> *ACCURACY*
> _Seiko claims that the caliber 7T62 will maintain accuracy of +/- 15 seconds per month at normal operating temperatures of about 41F to 95F. The alarm is accurate to +/- 1 minute._
> ...


Well, I suspect he wants to show that his watch has lost just one second in three months, so at -4spy it may not be advertised as an HAQ but it's way better than most of the HAQ watches around.


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## gaijin (Oct 29, 2007)

fmc000 said:


> Well, I suspect he wants to show that his watch has lost just one second in three months, so at -4spy it may not be advertised as an HAQ but it's way better than most of the HAQ watches around.


The data shown are in whole seconds only, i.e. +1.00 and +2.00 only. This indicates a rather crude measurement protocol.

There are no accompanying temperature data - just "mostly off wrist." 

Almost ANY quartz watch, when measured imprecisely and maintained at an optimal temperature, can exhibit data that appear to be indicative of HAQ performance; but that is not the case.

HTH


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