[newbienoob]

Thanks for the very helpful reply, svorkoetter.

I am actually timing it with 3 things... (1) My ipad stopwatch app, (2) an App that supposedly uses atomic clock and (3) my iphone stopwatch app.... granted, all three are electronics. I'll try with the quartz as you suggested. Now where did I put my seiko...

BTW, would there be any situation, based on your experience and knowledge, that would cause a watch to appear normal under the timegrapher but in actual fact has an issue? Or is it like the 'final authority' on accuracy?

 

[svorkoetter]

A timegrapher only measures the speed (called the "rate") of the watch during the period of time that it is doing the measuring. Any mechanical watch will change its rate throughout the day, to varying degrees, depending on:

• How wound the mainspring is (less of a problem with an automatic that you're always wearing, since it's always almost fully wound).
• Ambient temperature (less of a problem if you're wearing the watch, since your wrist will keep it fairly warm).
• Position (e.g. dial up, crown up, crown down, etc.)
• Sudden shocks, which can speed up or slow the watch down momentarily.

Testing on a timegrapher can really only compensate for position, by taking an average of six positions.

For a good quality watch movement, which your Rolex will definitely have, ambient temperature and position won't have a huge effect, especially not over the course of just an hour or two.

That leaves sudden shocks. Do you do something vigorous, such as playing tennis, golf, or football, during the period where the watch suddenly gains a few seconds? Do you have a car with a bad suspension and you drive it home on a bumpy road, with your watch hand on the steering wheel? That sort of thing is the only thing I can think of that could cause an actual short-term variation in rate (as opposed to a measuring error).

A poster in the other thread where you asked about this temporary speed-up said you should only measure a watch over a long period, but if short-term variations like the one you are seeing occurred routinely without cause, then adjusting a watch on a timegrapher would be useless, which is definitely not the case.