what's a reasonable amount of time to gain/lose?

[deejuic]

I'm gaining about 1 min per month w/ my IWC Portuguese Chronograph. It's only about 8 months old. Is that acceptable, or should I have it adjusted?

[Strangely Brown]

That's about 2 seconds per day, which is within COSC chronometer specs. That's actually pretty good for a mechanical watch.

[lowdrag]

According to the COSC certification, it is + or - 6 seconds a day I believe.

[Revs_Addiction]

That's excellent accuracy!!

By my maths, that's 99.997% accurate!!

Don't forget that ALL watches run slightly fast when they come out of the factory. This is to allow the movement to slow slightly, and become more accurate over time, as the lubricating oils within increase in viscosity as they become older....

[Stefan Tapp]

I'd be happy with that. COSC is -4 to +6 I believe. My Breitlings range from +1 to +4. I did buy a new Breitling Super Avenger back in November that was running at +8 seconds a day, but it went back and now runs at +1 a day. I think my Seiko 5 runs about +2 seconds a day.

Stef

Edited by Stefan Tapp on Friday 30th January 08:25

[deejuic]

I thought that was pretty good, but wanted to confirm.

Thanks.