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Re: wristwatch chronometers
From: Alexandre Eremenko
Date: 2012 Apr 18, 19:33 -0400
From: Alexandre Eremenko
Date: 2012 Apr 18, 19:33 -0400
Of course it is unfair to compare mechanical watches with quartz ones. And certainly many cheap quartz watches will outperform any chronometer. I have a quartz watch ($200, which is not exactly cheap for a quartz watch) which will be off 2-3 seconds PER YEAR without any adjustment. So mechanical watches should be ony compred with mechanical watches. Now, the table you refer to gives the accuracy criteria which may be reasonable for for a wristwatch, but not reasnable for a chronometer. For example, they say that a typical modern mechanical watch which is "certified as a chronometer" must have a rate +/- 3 sec/day. This is a meaningless number for a chronometer. Good marine chronometer is not a watch whose rate is small but a watch whose rate is CONSTANT. Think of a chronometer which will have +3 sec rate for 10 days and -3 sec rate for some other 10 days. Is this chronometer useful for determination of longitide? Not much. The difference between a "good wrist watch" and a chronometer is very visible when I compare my chronometer to a good wristwatch for a month or so. Alex.