COSC Movement Accuracy

Thread: COSC Movement Accuracy

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  1. #1
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    Confused COSC Movement Accuracy

    Hi folks,

    I'd like you're opinion on this one - my Airman No/Logo with COSC movement is currently running at +7 secs/day consistently (After sending it back in November 2008 when it was running at -4 secs/day).

    After speaking to Regine, she has stated that the COSC movements are regulated up to +10 secs/day and after me pointing out to her that the COSC specs are -3 to +6 sec/day she has offered to take the watch back to regulate it to +3 secs/day (At their cost). All this shows the extent that Stowa are willing to go to, but am I being picky with this?

    The reason I ask is that if Stowa COSC watches are regulated up to +10 secs/day (And this would be deemed acceptable) I don't really want to be a pain and cause Stowa undue costs!

    So, the question is - is it reasonable for me to expect the Stowa watches with a COSC movement to perform within COSC specs?

    I would like to stress that this is not a criticism of Stowa, as I appreciate the offer currently made, and is merely a check to see if I am being excessive in my expectations.

  2. #2
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    Re: COSC Movement Accuracy

    Take it easy, I wouldn't send it anywhere, this will improve by time and you have a great watch. Your are right, should be between -2 - +6 seconds, but I wouldn't take it so seriously. Otherwise a good watchman can easily regulate a mechanical watch where you live, I have never sent a watch back just for regulation.
    Just my advise.
    Last edited by deOwar; January 30th, 2009 at 14:50.

  3. #3
    Member Erik_H's Avatar
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    Re: COSC Movement Accuracy

    Do you take it off during night? Do you always place it in the same position, let's say on the side with crown up? Try changing the resting position, it may affect the overall performance. Old railroad grade pocketwatches were regulated in 5 or 6 positions to balance the fact that a watch will perform differently in any given position. However this is a very timeconsuming and labour intensive process, and not used on modern watches.

    Please disregard if you have already tried this.
    Erik_H
    Member NAWCC Chapter 149

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  5. #4
    Member Ray916MN's Avatar
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    Re: COSC Movement Accuracy

    If your watch came with a COSC chronometer certificate you have every right to expect it to perform within COSC specs as it had to be tested to these specifications to get the certificate. There is no such thing as a COSC movement. COSC only issues certificates on the movements it has tested.

    If your watch has a movement for which COSC certificates have been issued, it is not reasonable to expect the movement to perform within COSC specs.

    COSC testing is in effect a quality control measure which helps select movements for which all the mechanical tolerances add up to high accuracy. All movements of a given caliber should not be expected to perform to COSC specs, because some have been shown to perform to this level. The most obvious example of this is the ETA 2824 movement, for which COSC certificates have been issued and which is the most widely used and produced Swiss automatic movement, but usually doesn't run to COSC specs.

    To get the greatest accuracy out of your watch have it regulated locally at an average temperature in multiple positions.

  6. #5
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    Re: COSC Movement Accuracy

    COSC movements when they are tested and certified are not done in the watch, so it is up to the watchmaker to do the final work.

    1. Any good watchmaker can regulate the movement - COSC movements are designed to be more stable than standard movements anyway.

    2. I do my own regulating of watches out of warranty, including COSC (and all) movements to 4 positions only, with one of them being the largest focus - the "desk sitting" position, which is a combination of 12 down and face-up, the watch at 30 degrees, crown facing down only slightly. It's the position my wrist would be in when sitting at a desk, driving, and in general. Then I look at 12 down, face-up, then crown down, in that order. Re-regulating a watch in all positions means that it is an average, and the greater the variance between all the positions, and the more positions, the more it generally washes out its timing. My regulating the watch face-down and 12 up and crown up has little meaning because the watch is rarely in that position anyway, so I only use those as a reference to see how stable is the movement.

    3. Chances are, if your local watchmaker takes plenty of time to do the work and looks at regulating the 2824-2 in "real world" positions, you will find a better regulated movement.

    Hope this helps,

    Glen

  7. #6
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    Re: COSC Movement Accuracy

    I have an Antea COSC for more than a year now. First I watched its accuracy every hour or so (crazy eh? - the right a guy from the quartz-world..). Because I thought I payed for its certificate, oh man. It ran sometimes +10-15/day. I mailed to Stowa that "hey, what's going on with my watch", and blabla. Now I know it would be better to consider the "take-it-easy" way:

    After a 1-2 month or so ("wear-in period") it began to be accurate according to COSC. Now sometimes it's about even +-1/day. But I don't care so much anymore. I learned to love as it is, and learned that the accuracy is important though, but not the only thing to die for.

    The attached image contains a chart about the first 7 months of my Stowa Antea COSC. Those big spikes at the end can be my faults too, sometimes I was lazy to be as accurate as my watch

    Conclusion (as written several times): COSC == high quality. Not just accuracy. It's personal taste, I didn't regret it to pay the extra prize for it, because I'm sure that my grandchildren will hear it's ticking, too.
    Attached Images Attached Images


  8. #7
    stuffler,mike
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    Re: COSC Movement Accuracy

    Quote Originally Posted by mizu View Post
    I have an Antea COSC for more than a year now. First I watched its accuracy every hour or so (crazy eh? - the right a guy from the quartz-world..). Because I thought I payed for its certificate, oh man. It ran sometimes +10-15/day. I mailed to Stowa that "hey, what's going on with my watch", and blabla. Now I know it would be better to consider the "take-it-easy" way:

    After a 1-2 month or so ("wear-in period") it began to be accurate according to COSC. Now sometimes it's about even +-1/day. But I don't care so much anymore. I learned to love as it is, and learned that the accuracy is important though, but not the only thing to die for.

    The attached image contains a chart about the first 7 months of my Stowa Antea COSC. Those big spikes at the end can be my faults too, sometimes I was lazy to be as accurate as my watch

    Conclusion (as written several times): COSC == high quality. Not just accuracy. It's personal taste, I didn't regret it to pay the extra prize for it, because I'm sure that my grandchildren will hear it's ticking, too.
    Quite interesting. Thanks for sharing.

  9. #8
    Member Wile's Avatar
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    Re: COSC Movement Accuracy

    Yes, very interesting chart. Have to compare it to my Antea COSC when it arrives. Thanks for sharing!
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  10. #9
    Member Cursor's Avatar
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    Re: COSC Movement Accuracy

    I think you're not being unreasonable. But I also think you might be being a little hasty--as others are pointing out. The position the watch is in and other external factors may be throwing your watch slightly off. But perhaps it really bugs you--and if it does, that's why you buy a Stowa.

    Other manufacturers would tell you to get bent or send your watch back to you maybe in worse condition (see some of the shocking stories about the New Jersey Swatch Group service center in the Omega forum) while Stowa will stand behind their products 100%.

  11. #10
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    Re: COSC Movement Accuracy

    I'd probably try doing what some of the other members have posted first...but i think it is well within your rights as a customer to make this request. Afterall, you did pay extra for the COSC certified movement.

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