[time-nuts] Clock Calibration

Chris Albertson albertson.chris at gmail.com
Thu Jan 27 23:52:49 UTC 2011

On Thu, Jan 27, 2011 at 12:55 PM, Perry Sandeen <sandeenpa at yahoo.com> wrote:

> ...how the heck they were able to calibrate a clock to milliseconds per day back then?

Let it run for 1,000 days, then you only need to be able to measure to
the nearest second to get to ms per day.  Or maybe you can measure to
0.1 seconds so it only takes 100 days.

The trouble is that using this method you don't know the average
error.  A good example is an eccentric gear that makes a second hand
run fast then slow but if averaged over a long period is near perfect.
 I doubt they were able to catch stuff like that.

Chris Albertson
Redondo Beach, California

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