[time-nuts] Tissot wrist watch

Tom Van Baak tvb at LeapSecond.com
Wed Apr 6 18:44:49 UTC 2011


Although we normally deal with nanoseconds and picoseconds
here on this list, the essence of being a "time nut" and the allure
of precision timekeeping is there in the micro- and milli-second
world as well. I can personally tell you that the Allan deviation of
a pendulum clock is equal or more interesting than an H-maser.

As Bill just mentioned, for those of you interested in wristwatch
or pendulum clock timing, please see Bryan's site:
http://www.bmumford.com/microset.html

Antonio, I used one of Bryan's Microset timers to measure my
(WWVB radio controlled) wristwatch:
http://www.leapsecond.com/pages/Junghans/

There's no need to wait a month before you see a 1 second
error! -- If you can measure to 1/10 second you only have
to wait a few days, right?

If you can measure to 1/1000 second you can see the error
within an hour. If you use a Microset  measure to 1/1000000
second you can time and rate errors within seconds or minutes!

But at this level you will also be able to measure variations due
to temperature or humidity or pressure or orientation, or phase
of the moon, etc. You can monitor time, rate over time; rate drift
over time; rate over shock, etc. The Microset is really nice.

Note that just because your watch is accurate to 1 second a
month does not mean it will be accurate to 12 second a year
or 2 minutes a decade or 1/4 second a week or 1.4 ms an hour.
The extreme non-linearity in performance is part of the great
fun of analyzing the performance of any clock, in the short- 
and long-term, from mechanical to quartz to atomic clocks.

/tvb

> Dear Time-Nuts,
> 
> I am afraid of being off topic with the following.
> If so, I sincerely apologize.
> 
> I would like to know the precision to be expected
> on time keeping from a Tissot mod. J378/478 S wrist
> watch and how could be verified the fulfilment of
> that specification without waiting for a long time
> (probably more than one month) to observe an error
> of one second.
> 
> Instructions on how to build a test basket or similar
> layout would be most appreciated.
> 
> Thanks in advance,
> Antonio
> CT1TE





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