zOwie Omega Discussion Forum

: Hi again,

: I am wondering how accurate is reasonable to
: expect my seamaster chronograph to be after
: servicing. It is 11 years old now, and has
: never been a reliable timekeeper (always
: been slow, but I think a questionable
: service or two has been involved). I see
: posts of folks on various boards reporting
: getting their watches back and having them
: run +- 2 seconds a day, well better than
: chronometer standards, it seems to me. Do I
: just need to find a better watchmaker?
: Change my expectations? And what does
: "regulating" a watch really mean?
: Is that anything more complicated than the
: guy putting my watch on some sort of
: oscilloscope or whatever the amazing gadget
: is that he uses to tell whether the watch
: runs fast or slow? Thanks for anyone patient
: enough to educate the new guy!!!!

: Thanks yet again,
: Jimmy Penson

Since the COSC specs are -4 to +6 sec/day, both Omega and independent watchmakers should make sure the watch is running within this range before returning it to you. This is really the "acceptable" range for a certified chronometer like your Seamaster chronograph.

That being said, the better the watchmaker, the better your chances are of him being able to regulate your watch as close to zero as possible. As an example, my Bond SMP had been running at +4 to +5 sec/day out of the box. After a regulation from my watchmaker it has continued to get better, and at last check it had only gained +0.10 sec/day over a 49 day period.

Regulation involves making fine adjustments to alter the rate of the rotor's vibration. Your watch's rotor completes 8 vibrations per second, so in 24 hours your watch should vibrate 691,200 times. If it vibrates 8 extra times in this 24 hour period, your watch will gain 1 second. If it misses 16 vibrations, your watch will lose 2 seconds. Some movements are easier to regulate than others, so the movement and the skill of your watchmaker are the biggest factors in determining how well your watch will keep time.