timing

[TimFitz]

Hi

Can anyone point me in the direction of finding a chart of beat rates for american pocket watches?

Thanks

Tim

[Gpsluvr]

You probably know this, but count the beats of the secondhand per second and multiply times 3600. 4 beats is 14,400 5 is 18000. If you have the watch and it is running of course.


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[TimFitz]

No I didn't know that, but what is the perfect number of beats for any particular watch? I assume there must be a chart or a list of recommendations?

Tim

[Gpsluvr]

The beat rate is set in the design of the watch and can’t be changed to any extent. The goal of accuracy is to achieve the perfect rate. If you have a watch that beats at 18000 per hour, you are trying to hit exactly 18000, not more or less. A watch might have an accuracy of plus 3 seconds a day, which means if it was an 18000, that it was 15 beats fast for the whole day. That is adjusted by mechanically shortening or lengthening the hairspring that drives the balance wheel. Other factors are in play as well, in the overall accuracy, not just the hairspring.


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[TimFitz]

So if I'm reading this correctly, is 18000 beats per hour is the standard for all American Pocket watches.

[Gpsluvr]

Not exactly. All watches including pocket and wrist and desktop can be designed to tick at 3 4 or 5 beats per second. The faster ones can provide better possible accuracy but they have a higher amount of wear and tear, so its a trade off. There are no standards across brands or types per se. you just have to examine the specs for each movement number manufactured to find what rate they designed it for. You can’t change a movement from one rate to the other, either because the gear ratios would all have to be changed as well.


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[JohnR725]

American pocket watches typically run it 18,000bph. If it is extremely old then 16,200 bph.