Vibration galvanometer

The vibration galvanometer is used for detecting alternating currents in the frequency of its natural resonance.

Most common application is as a null indicating instrument in AC bridge circuits and current comparators.

The sharp resonance of the vibration galvanometer makes it very sensitive to changes in the measured current frequency and it can be used as an accurate tuning device.

[1] The frequency-sensitive behaviour of the galvanometer allows their use as a crude frequency meter, commonly used for adjusting the speed of AC generator sets.

The magnets are conveniently constructed as a single iron 'comb' of individual reeds, each of different length.