# Accuracy of Longines automatic watches - post your results!



## covalatte

I thought this might be an interesting thread.

When I timed my Longines Master collection Moonphase against my computer, I was surprised to find an error of 0 seconds after 12 hours! Basically I synchronised the computer to my Longines (easier than the other way I think), and put the two side by side to compare.

I was prepared to see an error of up to 15 seconds over 24 hours, and was hoping for less than 10 seconds, but I must be lucky.


What kind of results is everyone else getting?

Will update this post with the error at 24 hours!


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## Seiko_Licker

I'm getting a fairly consistent +10 seconds/24 hours on my Hydroconquest.


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## covalatte

At 24 hours, mine is still at an unappreciable error when compared side to side with my computer. 

First 12 hours the watch was left still, and 2nd 12 hours I wore it.

Pleasantly surprised about this result. Think I got lucky.


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## ugly

I have two Longines :
+ 12 sec/day on hydroconquest
- 5 sec/day on hydroconquest chrono.


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## ArticMan

LLD no date


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## 3th3r

I don't have formal measurements, but I check My Hydroconquest's time often against my computer, which sync'd to a local NIST time server. When I first got the watch, it was about +2 secs/day, and a few months later, it is now about -1 sec/day. Whoever regulated this watch at the factory did a great job.


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## heb

A lousy, but consistent, +11 s/d for my WWW Military I purchased about 2 years ago. Wore it for two weeks when I got it and haven't since. I'll have to fire it back up some day and adjust it.
heb


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## The Elf

When I first got it, it was +5s, seems to getting more accurate as I have worn it more, but I haven't done a proper measurement on it since.


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## dr3ws

My hydroconquest chrono is running +10 secs a day, should I get it regulated? I know it's still within the range mentioned in the manual but I was expecting a little bit better


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## krabicka3

On my Master Collection Retrograde Power Reserve depends on the position - when I put it on the table crown up (9h down) it runs late about -2 seconds/24h. But when I put it dial up (horizontally) it runs +2 seconds/24h. So i regulate it accordingly.


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## GMJ

A great thread! My daily wear watch (the only one I check for timing accuracy) is the HC Chrono (new version in blue) which, like the Retrograde mentioned above, gains a little during the day, but at night (on bed side table, crown up) it looses what it has gained. I reset the watch every Sunday and overall, it gains about 5 seconds a week. That's better than COSC, so I'm very pleased with it.


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## heden

I got a Hydroconquest and it's gaining around 2.7 seconds per day. Very happy with this watch.


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## exelrod.gregory

I have few longines mechanical automatical watches , one of them - master collection retrograde watch passed guarantee maintenance but accuracy in all my watches about 15 second per 24 hours ? For example powermatic 80 certina automatically watch gain every day better than 7 seconds ? And price 1/5 of longines master collection automatic watches ?


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## Beena

I recently bought a Spirit 37mm and it has lost 7 seconds in total in five days. I’m really pleased with that.


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## Magna Graecia

My Hydroconquest runs -1 to -.5 a day, which is phenomenal for a non COSC movement.


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## oprhodium39

Just checked my Conquest VHP, about +2.5 sec compared to atomic time, I don't remember when I adjusted last time (maybe 2-3 months ago?)
(OK, it's not automatic, but has a very long - approx. 3 years - power reserve  )


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## sebis

My Zulu Time (COSC) runs -1 second after a total of 7 days. For the first 4 days was +0.5 seconds total. I am very pleased with it.

The Spirit Pioneer Chrono in Titanium on the other hand is at the limit of its COSC certification, -4 spd. Needless to say, I am tempted to send it for warranty claim as soon as it runs outside of the COSC specs.


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## domayotte

My Dolce Vita has been running a pretty consistent +1.5 seconds per day. Very steady performer. 










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## marek-zegarek

My Longines HydroConquest fluctuates between -8 to +10 seconds but overall is within a couple of seconds a day, either slow or fast. So with a bit of luck, I could finish the month with 100% accuracy.


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## dklap3

I’m very impressed with the accuracy of my first Longines, the 37 mm Spirit.

It’s somewhere in the -0,5 to +0,5 seconds per day range.


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## Beena

I am also impressed with the Spirit 37 accuracy. Mine runs around 2 seconds a week fast.


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## jaycwb

+3s on a 2 weeks period for my Zulu Time. Not too bad


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## Magna Graecia

My 43mm Hydroconquest is -1/spd. Very pleased with its accuracy.


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## JPa

I must be lucky. My conquest runs around -2 spd and my hydroconquest runs around +3 spd. Both get worn frequently in not so gentle environments.


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## HousePanther94

My Hydroconquest with the L888.5 has been running + or - 1-2 seconds a day, but always averages out to be almost dead on. I thought it was a fluke, but apparently Longines is serious about accuracy. My Certina auto is currently +9 spd and I used to be happy with that lol. 


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## semiprepper

How is everyone checking the accuracy? Are you putting it on a time grapher or just a visual check against time.gov or time.is?


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## akakovivi

My watch was the Longines Record L2.820.4 and I owned it for approximately 4 months.
Aparting from the "feeling way," I used Excel to estimate its time accuracy. I just very simply function and let Excel do the job, like this graph of showing part of my results. 
I check standard time from Time.is, then record its deviation in Excel every morning.
So far, the statistical result is 0.106s ahead. Is it real to move ahead by 0.106 per day? Perhaps not. Taking a look at the line chart, it has move cycling! And the Returns chart as well !
Ignoring that 0.05, that is feeling accuracy, which I use the intraday divides by the days I own it.
In the first month, I actually felt it move 0.5 s per day, something moving 0 s. But when we go to the second month forward, its deviation gets bigger, but still within the COSC range until now. I am very OK with that as long as you move within what you promised to our customers. Holy cow in our third month, as I have been travelling a lot. But this month, it's back to normal and keeping a small deviation. I feel great.
Does my watch have good time-accuracy? Yes for both feelings and statistics, but cannot ignore that deviation as the uncertainty activities in my daily life. Despite, I enjoy it. 
A small empirical test lets me know more than I just owned it. Changing the position when you take it off could adjust the time accuracy for tomorrow.
Do you think my watch has good time-accuracy?


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## semiprepper

akakovivi said:


> So far, the statistical result is 0.106s ahead.



You’re visually estimating .1 sec/day variance a day or are you estimating time variance over week or month and dividing the # of days?


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## akakovivi

semiprepper said:


> You’re visually estimating .1 sec/day variance a day or are you estimating time variance over week or month and dividing the # of days?


=avg(all samples of the return)


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## Pexel

I've been wearing my Omega lately so my Hydroconquest has taken a back seat. I decided to wear it over the weekend, I first wound it then set the time according to www.time.is.

I noticed within the first 3 hours the watch had lost 20 seconds! I'm not sure if this a consequence of not having used it but this seems very strange to me.


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## domayotte

Pexel said:


> I've been wearing my Omega lately so my Hydroconquest has taken a back seat. I decided to wear it over the weekend, I first wound it then set the time according to www.time.is.
> 
> I noticed within the first 3 hours the watch had lost 20 seconds! I'm not sure if this a consequence of not having used it but this seems very strange to me.


Sounds like it might be magnetized…. 


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## mathu

I am able to stay at 0 average SPD with my Spirit Zulu Time. Being worn it loses 1s per day, but kept face up overnight it gains 1s again. If it loses too much I leave it for a full day, if it gains too much I wind it up to the max reserve (then it loses a bit more). So after 3 months I was able to stay at dead 0.


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## Kaboom25

Not a Longines watch but a Longines movement



















Got the movement off EBay still in its sealed Longines packaging. Bang on 0s/d dial up on the timegrapher and very little positional variance, 3s at most between all 6 positions. After a whole week on the wrist and dial up in the box at night it had gained a full 2 seconds.
By far the most accurate mechanical watch I own, needless to say I'm very satisfied.
That's how it came out of the packaging too, I thought I would regulate it but it certainly didn't need it!


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## Pexel

domayotte said:


> Sounds like it might be magnetized….


OK, I've tried the iOS app and it reported it was magnetized! I have now demganetized the watch and the iOS app no longer reports it is magnetized and overnight it seems to have only gained 1.9 seconds. I'm going to keep a close eye on it, thanks for the response.


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## HousePanther94

I’m very impressed with the performance of my L888.5. It’s never more and a few seconds off when I check it, and I haven’t set it in over a week. Although my Mido caliber 80 in my ocean star has been right there with it. Not sure if that’s a fluke, but both are running well within COSC spec. 


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