Accuracy of Mechanical watches
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in determining the grade of a watch, many times the number of jewels has been used a general rule of
thumb. While a watch with 17 to 23 jewels can be adjusted with regards to position, temperature, and thumb.
While a watch with 17 to 23 jewels can be adjusted with regards to position, temperature, and isochronism
(the ability to keep constant time throughout the wind cycle of the mainspring) rendering a high degree of
accuracy, a properly adjusted 7 jewel watch can be reasonably accurate as well.
degree of accuracy, a properly adjusted 7 jewel watch can be reasonably accurate as well.
Accuracy also depends on how the watch is worn. For example a watch that is laying on your nightstand
most of the time will run at a different rate than if you use it everyday (i.e. On its back or ‘dial up’ during the
night, and ‘pendant up’ in your pocket most of the day). While some variation in rate may be observed over
short periods of time, this is often smoothed out over a days routine.
Other factors such as temperature, how long since the last service, and wear of parts can affect time
keeping. That is why if you want to use the watch on a regular basis, then it should be serviced every 3-4
years.
