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The following pages are a glossary of terms associated with horology, watches and watchmaking. Please click on one of the links or glossary terms below to learn more about them. Most of the terms are enhanced with detailed imagery. If you would like us to list any other words that you think may be helpful, please contact me direct email@example.com. We will update the glossary frequently.
V – WATCH WORDS
In horology the term is usually referred to the variation of the daily rate, i.e. the difference between two daily rates specified by a time interval.
Vibration Frequency (VPH)
The ring-shaped balance swings around its own axis and acts as the ruling organ of the movement’s escapement. Its amplitude (normally about 300 degrees) is restricted by the very thin balance spring, which also provides for the reversing of its direction of rotation. The frequency of the alternating vibrations is measured in Hertz (Hz) or in the more usual vibrations per hour (vph).
The most common frequency for modern mechanical wristwatch movements is 28,800 vph (or 4 Hz) like our own Malvern Automatic. A watch ticking at 4Hz makes 4 oscillations per second, or 8 semi-oscillations (or vibrations) per second. There are 60 seconds in a minute, so this watch would tick at 480 semi-oscillations (or vibrations) per minute. Multiplying the 480 vibrations per minute by the 60 minutes in an hour yields the 28,800 vph figure. Since this watch ticks 8 times per second, a chronograph in a 28,800 vph watch can time events to the nearest 1/8 of a second.