Forums Latest Members

What variance does a watch run "accurately"?

  1. NYCwatchgal Apr 7, 2019

    Posts
    278
    Likes
    881
    What is the standard variance for a modern AND vintage mechanical watch to be considered running "accurately"? ± 3 seconds?
     
  2. Bushido Apr 8, 2019

    Posts
    1,059
    Likes
    2,414
    Are you thinking along the lines of the accuracy tolerances of a specific movement or a more general subjective definition?

    Chronometers (COSC) are listed as -4/+6s per day. Omega lists their specific chronometer tolerance to be -1/+6s per day.
    Omega's non chronometer movements (like the 1861) are listed at -1/+11s per day.
    METAS movements are listed at 0/+5s per day.

    As a more general rule for me? If I'm not having to correct the time too often, it's accurate enough.
     
  3. Dan S Apr 8, 2019

    Posts
    18,513
    Likes
    42,683
    There is no fixed standard. As mentioned above, most modern movements have specifications. As you may know, the variation reflects measuring timekeeping in various positions. @Archer started a great thread on this: https://omegaforums.net/threads/tim...-understand-how-they-work.87293/#post-1128576

    Regarding vintage watches, I think it's not always realistic to demand that they meet the same timekeeping standards that were specified when they were new, since they may not have been serviced regularly and various parts may have experienced significant wear. Yes, we have all had experiences where a vintage watch keeps excellent time, but not always, and trying to bring an old watch back to very high timekeeping standards can be difficult and expensive.

    So personally, I have lower standards for vintage watches, but it is something of a sliding scale based on the age of the watch, the ease of obtaining replacement parts, and the sophistication of the movement. For example, I have higher expectations of a 1970s Rolex than a 1940s Eterna. For the latter, I would probably be satisfied if it is within 20s per day.
     
    Edited Apr 8, 2019
  4. Archer Omega Qualified Watchmaker Apr 8, 2019

    Posts
    26,301
    Likes
    64,924
    No - not all of them. People tend to think of METAS as the same as COSC, which means a fixed standard applied to any watch with that certification, but that's not how it works.

    METAS certification is not a standard for timing in itself, it's just confirmation that a watch is meeting the standard that the watch company set for itself.

    This means that METAS certification and Master Chronometer watches can have very different ranges depending on the movement in question. For some it's true that the range for average daily rate is from 0 to +5, but for some movements it's 0 to +6, and for some 0 to +7.

    So for the Cal. 8900 movement it's 0 to +5, but for the new 8800 movements it's 0 to +6, and for some others like the Cal. 8700, it's 0 to +7 s/d for average daily rate.

    Cheers, Al
     
  5. NYCwatchgal Apr 8, 2019

    Posts
    278
    Likes
    881
    Thanks Bushido. I was thinking more of a general subjective definition.

    That's a great general rule of thumb. I like that :)
     
  6. NYCwatchgal Apr 8, 2019

    Posts
    278
    Likes
    881
    Thanks Dan for the Archer/Al's link. Will read up on it. I also read in Hodinkee's article that Rolexes can be +/- 2 seconds whereas others can be 30 sec/day.

    https://www.hodinkee.com/articles/how-accurate-should-your-mechanical-watch-be

    I agree modern watches should be more accurate than vintage and 20 secs is a good measure to abide by. Thanks as always!
     
  7. Archer Omega Qualified Watchmaker Apr 8, 2019

    Posts
    26,301
    Likes
    64,924
    Note that the article you linked to is not accurate. In particular this section:

    "Rolex, Grand Seiko, and many other brands routinely publicize their accuracy and precision requirements; if you buy a Rolex today, you should expect it to be accurate to +2/-2 seconds per day, at most, full stop. Grand Seiko Hi-Beat movements are spec'd to +5/-3 seconds per day, and that's what you should expect."

    If you read the thread linked above, I explain in some detail why the range for average daily rate will in no way guarantee that the watch will be in that range "at most, full stop" as is suggested in that article. He has some additional knowledge gaps to fill I think...

    Cheers, Al
     
    Premaster, NYCwatchgal and kkt like this.