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Casio make a 4Mhz AT cut thermoinsensitive digital watch. There is some question about its accuracy on the ground but its theoretical capability would be a double figures seconds a year.

There are some digital variations upon the ETA autoquartz made by Ventura which have very high accuracy claimed for them. While they are high quality movements which are possibly the only multi jewelled digital quartz on the planet they are not thermocompensated and so I am personally sceptical.

Some of the analog/digital quartz stuff from Brietling combines a digital read out and thermocompensation. The Brietling B1 is as good an example as any. However, I'm not sure that this is what you want...

I have heard rumours of an old thermoinsensitive Citizen digital but nothing concrete.

That's about it for me.
 

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Yeah, re: the Breitlings,... the B-1, Emergency, Emergency Mission and Avantage (Airwolf, too?..not sure) all contain thermocompensated movements..they're all ana-digi's as well...Breitling doesn't currently produce an all digital watch..

The Omega X-33 is pretty sweet as well...gotta buy NOS at AD (if still has one) or pre-owned..its no longer sold to general public as far as I can tell.
 

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Yes, Sjoo Sandstrom had one spec'ed to 10 seconds/year, AFAIR. It is long out of production and except for some Forum help, I have not read about any others.
 

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Casio make a 4Mhz AT cut thermoinsensitive digital watch. There is some question about its accuracy on the ground but its theoretical capability would be a double figures seconds a year.
Here is a scan of my Casio 4 mHz digital. These are very scarce watches. I have only seen one other scan. Timekeeping is just normal for a quartz, nothing special. I am thinking about doing a test to determine if it is thermally insensitive, but that will have to wait for cooler weather.



 

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You could always just put it in your refrigerator ... :-d
Three - make that four problems:

  • Much to simple a method for a true WIS - the experiment must involve complicated electronics and state of the art temperature control.
  • Fridge is much colder than you would likely see inside your home or on the wrist.
  • Not good temperature control in the fridge.
  • Wife would think I was even stranger than she does now.
I may try going up from the current temperature in my environmental chamber (read - egg incubator) from 84 F to say 92 F or so. That is usually enough to get a reasonable change in a non-compensated movement.
 
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