What is considered as a watch that needs calibrating?

[blue lion]

I'm checking my Sub to see if it keeps correct time.
How many seconds off of the official time is too many?
How often do you check that? Once a month or what?
Thanks.

[gwalker]

I'm happy with 4-5+\- secs a day. COSC is +6/-4.

[Megalobyte]

I'm happy if my Sub C outperforms a good quartz, though I suppose I can settle for a bit less. :)

The real trick for a newbie is to make sure they're getting an accurate reading, which depends on state of wind, and checking against a reliable time source properly.

[padi56]

Originally Posted by Megalobyte

I'm happy if my Sub C outperforms a good quartz, though I suppose I can settle for a bit less. :)

The real trick for a newbie is to make sure they're getting an accurate reading, which depends on state of wind, and checking against a reliable time source properly.

I would say that's impossible for any mechanical watch to out-perform a good quartz no matter your reliable time source or brand.Many good quartz especially the ones from Seiko and Citizen are capable of +-2 seconds a year.Afraid no mechanical watch any brand could achieve such accuracy.And in most case even a cheaper quartz that accurate to -+ 5 seconds a months will be far more accurate than any purely mechanical watch.And today if any mechanical watch can perform too, or a little out side the COSC spec. Which is a average of -4+6 seconds over any 24 hour period well those few seconds out of the 86400 in a day is a mechanical marvel

[77T]

When I depend on accurate time, I check daily and hack to the best source available. Otherwise I verify weekly. But I would not worry if it was off by a few seconds up or down during a 24-hr. stretch.

When you notice things like 30 seconds lost or gained in a day, it's time to try some regulation. It's interesting that some of my different watches have their own habits. A few are within a few seconds even after a week or more. One may gain a minute a week while another lose the same amount.

[blue lion]

I'm not worried about much, but I want to know what is normal and what is not.
I have a Z Sub and it's about due for a RSC service based on years but if it's keeping good time I'm fine.
Thanks.

[77T]

It will keep good time even as the lubricants dry out - but the gaskets replaced during a service is more important with a Sub if you take it deep. Agree 6 years is a good time to begin thinking service - wouldn't go past 10 years with a duty Sub though. Maybe have a pressure test soon? Then you'll know it's OK.

[dddrees]

Anything from -4 to +6 is within standard. In order to check your watch it is best to give it 40 winds and set it according to an accurate time source. Check it at the end of 7 days and then check your average.

[azguy]

Originally Posted by dddrees

Anything from -4 to +6 is within standard. In order to check your watch it is best to give it 40 winds and set it according to an accurate time source. Check it at the end of 7 days and then check your average.

x2

[kilyung]

Ultimately, only you can determine what's acceptable or not. I could live with +15s/d but most could not.