What "vph" means
Vibrations per hour — how often the balance swings. The seconds hand moves once per swing, so you can see the beat rate. Watch the dial and switch between them.
- 18,000
- 2.5 Hz · 5 beats/s · common in vintage
- 21,600
- 3 Hz · 6 beats/s · the NH35, most mods
- 28,800
- 4 Hz · 8 beats/s · most modern Swiss