Effect of low temperature on automatic watch function?

[NewToWatches]

When wearing an automatic watch, my wrist's natural warmth transfers to my watch.  But I live in a snowy clime and my "workshop" is unheated when not occupied.  Any sense of the effect of low temps on watch function?  If it gets down to, say, 3 F/-16 C at night, do I need to warm things up before I can trust my Timegrapher?

[KOwatch]

The balance wheel should exibit temperature isochronism, a lot of development over the last hundred+ years to prevent alteration in frequency from temperature.  If you're wearing your watch outside your parka (so you can see it) in the arctic, you'll want to get your watch serviced with an oil that's designed for low temperature, it has a different viscosity so it has correct performance at the target temperature range.

Cold weather would in theory thicken regular watch oils and slow the watch, you'd have to measure to determine how much (outside the regular variability of your watch)

[KOwatch]

Re-reading your question, there's a second part: what is the temperature isochronism of your timegrapher? I don't really know the time regulation circuit, assuming it's similar to a quartz watch using a quartz crystal, (might be mems?) the crystal will change in frequency depending on temperature (although much less than a mechanical watch). This should be thermally compensated (ideally), but there must be some remaining temperature-related variability, and that should be stated in the (quality?) manual.

http://www.leapsecond.com/hpan/an200-2.pdf

Good writeup on various factors effecting quartz frequency stability. It depends on a bunch of things, including temperature and age and design of the crystal, uncompensated temp variability might be something like  5ppm/degree Celsius, so over 36 degrees (room temp 20c to overnight temp of -16c) that's 180ppm, or 0.018%, or 15 seconds per day if my math is correct here (86400*.00018). That's pretty large, so you would expect it to be thermally compensated, but who knows? I think quartz crystal are designed for stability in  a temp range and then they drop off stability. I would warm up your timegrapher to within operating temperature specs before expecting expecting accurate readings.

 

 

[NewToWatches]

Many thanks!  As usual, you all are thinking about my questions in multiple dimensions I hadn't even considered.   Much appreciated.

[canthus]

Found this in my archives.  Don't know the owner/source or if any copyright issues.  If administrator is not happy about it please remove.

 

 

Oil Properties.xls

Edited January 26, 2021 by canthus

[PastorChris]

My only experience with such things is with mechanical cameras. I have a few older Leica fully mechanical cameras and they tend to have shutter release problems below about 20degF so they need to be kept inside you parka and taken out only for quick use.

For the famous Leica ///c series during WWII they made a special version with ball bearings in the film transport and I believe used special lubricants especially for winter use. You know, so the Germans could take photos of their glorious victories on the eastern front.

[NewToWatches]

*1 On Leicas.   On the plus side, the older M's had no battery to die in the cold.   I have a couple of these. . . an M2 with a modern Rapidwinder on it is a particular favorite.  Then again, it is never surprising that folks who appreciate mechanical watches also like mid-century tech that is as refined as a Leica.  The M3 with a 50mm lens and its 1:1 finder can be used with the shooter's right eye to give you a both-eyes-open head's up display on the world.  Pretty darn cool.  Also true of the Nikon S2.