The effects of weather upon automatic watches.

[Eleven]

Over the past week I've been checking the timekeeping on 3 Rolex chronometers.

In the past two days, two of the three that were slightly fast are now slightly slow. One that was very fast is now a bit slower.

Is this weather / temperature related?

[TimLambert7]

Surely temperature will have an affect on the viscosity of lubricants and potentially alter the running speed?

What variation in temperature have they been subjected to?

[Eleven]

TimLambert7 said:

Surely temperature will have an affect on the viscosity of lubricants and potentially alter the running speed?

What variation in temperature have they been subjected to?

Only whatever temperature difference there has been in my safe from one day to the next.

[Harvey Mushman00]

I doubt it.

[CardShark]

Eleven said:

Only whatever temperature difference there has been in my safe from one day to the next.

So a marginal difference then, I'd have thought. When you've checked them did you move them at all? The position of the watch, as in dial up/down etc, would influence the run rate more than any change in temperature in a safe IMO. The state of each watch's power reserves could also play a part.

[Eleven]

CardShark said:

Eleven said:

Only whatever temperature difference there has been in my safe from one day to the next.

So a marginal difference then, I'd have thought. When you've checked them did you move them at all? The position of the watch, as in dial up/down etc, would influence the run rate more than any change in temperature in a safe IMO. The state of each watch's power reserves could also play a part.

They do get moved yes. But they are in the same positions now as they were when they were gaining and they are wound daily.

[gbbird]

Who cares? Live with it. Anything mechanical will have it's differences

[glazbagun]

Temperature compensation has been an obstacle to correct timekeeping for centuries, going right back to when the pendulum was new technology. It's another reason why a good ships chronometer cost a fair chunk of the value of a ship. More than oil, it's effect is on the oscillator. The balance will expand with heat and the hairspring will become more elastic.

Charles Guillaume won a nobel prize(!) in 1920 for his efforts in creating Invar (an alloy which expands very very little with temperature) and later Elinvar (an alloy which maintains a very similar modulus of elasticity as temperature changes). These two things made balances much easier to manufacture, a total game changer!

Before that (back in the ships Chronometer days, and on better quality pocket watches) you had split bi-metallic balances with tempered steel hairsprings which would have to be adjusted by a watch/chronometer maker at different temperatures. They would spend weeks testing them!

I'm ranting though, as regards your watches there's too many variables from your OP. Atmospheric changes won't be making a difference.

[anonymous-user]

In my opinion the only fair judge of a wristwatch is to wear it.

if all you have to to is nudge it back/forward a bit every couple of weeks then job done.