On Tue, 23 Mar 2021 09:43:17 +0000, Clive Arthur wrote:

On 23/03/2021 00:47, williamwright wrote:
On 22/03/2021 22:05, Clive Arthur wrote:

Actually they do calibrate them, against a very accurate and stable
crystal timebase in watch repairers.

Yebbut a watch runs at a comparatively constant temperature.


On your wrist in all weathers?

Bill

Comparatively. You don't put your watch in a fridge or in a low oven,
it's either on your wrist or in your house. That's much better than a
car. And if you do have it on during a snowball fight, that won't be
for long.

IIRC watch crystals have a temperature/frequency curve where the
frequency is a maximum at around 25'C and drops off either side.

I don't think they're in the watch business any more, but I visited these
people once:

https://www.ablogtowatch.com/hoptrof...earable-sizes/

(Hoptroff, that is)
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