Vibrations per hour

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Vibrations per hour or beats per hour (vph, VPH, bph, BPH) is a mechanical timepiece specification. It is used to express the frequency of a watch movement. [1] [2]

VPH describes the number of times that a vibrating timekeeping component completes half a vibration cycle every hour (counting the balance wheel's back and forth movement separately, as each produces a forward movement in the escape wheel). [3]

In contrast, when measuring the same frequency in Hertz, it describes the number of times that the component completes a whole vibration cycle in a second (counting pairs of forward movement in the escape wheel). The frequency in Hertz can therefore be multiplied by 7,200 (2 ticks × 60 seconds × 60 minutes) to determine the frequency in VPH.

A higher frequency is a higher timekeeping resolution, and usually indicates a higher precision mechanical movement. [2] This allows a faster recovery from being knocked or bumped, with the tradeoff being a faster accumulation of wear and tear.

References

  1. ↑ Fritts, C.E. (1904). The Watch Adjuster's Manual. The Keystone. p.  81 . Retrieved 13 September 2018.
  2. 1 2 "Vibration, VPH". WatchTime – USA's No.1 Watch Magazine. Retrieved 8 July 2018.
  3. ↑ Doerr, Elizabeth. "The Slowest Watch in the World". Forbes. Retrieved 8 July 2018.
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