Rolex service - how do they tell it's running accurate?

[brandobot]

I recently brought my watch to the Rolex service center to have them check if my watch was running accurate. They took it into the backeoom and told me it was running fine. I'm wondering if they had to open the caseback to check the accuracy of the watch. I'm mainly concerned if it was pressure tested if it had to be opened

[77T]

It isn't necessary to open it. They use an electronic device that measures rate and amplitude. As long as it falls within specs, "it is running fine".

[brandobot]

Thx!

[Sharpshot]

I noticed with mine after a few days my secs run faster then the time on my cell phone ? Like if it's turning let's say 10.20 on my cell phone and I watch on my sub when the time changes the next time around I check a couple days later and it's 2 too 3 sec faster on my sub .....I wonder if that's normal ?

[Sweetswisssteel]

Mine has gained 10secs since its return from warranty regulation 14 days ago. I am quite satisfied

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