Calibration numbers help

[dazooom]

Looks like my vintage GMT 1675 is running kind of fast. Over 50 seconds/ day. Had it checked out at local AD. Would greatly appreciate it if someone could explain what all these numbers mean. Sorry if this is common knowledge here on TRF.

[Frakis]

I’m not sure what the numbers mean, but at +50 seconds/day means a movement service is required. Enjoy that beautiful timepiece!

[Old Expat Beast]

The numbers on the left show the seconds per day that the watch gains when it is positioned like the pics in the "Position" column. The numbers on the right show the amplitude (degrees of rotation in the balance wheel) in the dial-up and dial-down positions. Those two numbers are acceptable, and the watch might just need to be regulated rather than serviced, though a service probably would be a good idea.

[SearChart]

Magnetism anyone?

[Old Expat Beast]

Originally Posted by SearChart

Magnetism anyone?

You're the expert Bas, but I thought magnetism added minutes per day rather than seconds?

[SearChart]

Originally Posted by Old Expat Beast

You're the expert Bas, but I thought magnetism added minutes per day rather than seconds?

Oh it's definitely not always like that, in most cases it actually looks something like these results.

[Old Expat Beast]

Originally Posted by SearChart

Oh it's definitely not always like that, in most cases it actually looks something like these results.

Thanks

[dazooom]

Thanks for the feedback.

Cheers

[AEC]

Originally Posted by Old Expat Beast

You're the expert Bas, but I thought magnetism added minutes per day rather than seconds?

This was my first thought. Amplitude looks great; rate hints at magnetization. It's an easy, zero-cost correction if so.

I'm surprised the AD who timed it didn't come to this same conclusion and offer to demagnetize it on the spot. Was it an in-house watchmaker who evaluated it?

[dazooom]

Originally Posted by AEC

This was my first thought. Amplitude looks great; rate hints at magnetization. It's an easy, zero-cost correction if so.

I'm surprised the AD who timed it didn't come to this same conclusion and offer to demagnetize it on the spot. Was it an in-house watchmaker who evaluated it?

yes, it was an in-house watchmaker at an AD.

[RayShepherd]

Originally Posted by Old Expat Beast

The numbers on the left show the seconds per day that the watch gains when it is positioned like the pics in the "Position" column. The numbers on the right show the amplitude (degrees of rotation in the balance wheel) in the dial-up and dial-down positions. Those two numbers are acceptable, and the watch might just need to be regulated rather than serviced, though a service probably would be a good idea.

I'm here for the knowledge

[Nikrnic]

I'd check to have it de-magnetised. I've heard of it adding seconds as well as minutes.

Sent from my SM-G900V using Tapatalk

[dazooom]

I'm gonna take your advice. I'll let you know how it plays out.

[dazooom]

Originally Posted by AEC

This was my first thought. Amplitude looks great; rate hints at magnetization. It's an easy, zero-cost correction if so.

I'm surprised the AD who timed it didn't come to this same conclusion and offer to demagnetize it on the spot. Was it an in-house watchmaker who evaluated it?

Sorry to say it wasn’t magnetism. Took it to AD and had it retested.