Most watchmakers will use electronic timing machines which essentially report an average rate. Having a watch adjusted in positions can be time consuming but this process strives to achieve the greatest accuracy the watch is capable of.
As mentioned the persuit of accurate timekeeping is one that can drive you nutty even with the benefit of modern equipment. But it's true, temp, mainspring, wear habits etc all have their effect which even a timing machine cannot factor in.
One thing though, I was taught that ideally watches (lever escapement)should be set to +10 s/p/d. This is to compensate for their inherent mechanical losses.
As mentioned the persuit of accurate timekeeping is one that can drive you nutty even with the benefit of modern equipment. But it's true, temp, mainspring, wear habits etc all have their effect which even a timing machine cannot factor in.
One thing though, I was taught that ideally watches (lever escapement)should be set to +10 s/p/d. This is to compensate for their inherent mechanical losses.
