Frequency Meters

Author: E.E. Kimberly

Commercial frequency meters are made in several forms. The most common form employs vibrator reeds of different lengths arranged consecutively in a row on a common mounting. The mounting-is caused to vibrate by a magnet whose exciting winding is connected across the circuit in the same manner as a voltmeter. The reed weights are adjusted so that, when the common mounting is vibrated within the frequency range of the reeds, the reed tuned to that frequency vibrates. A scale adjacent to the row of reeds is calibrated directly in frequency.

Another type of frequency meter employs the dynamometer principle. The accuracy of ordinary frequency meters of the non-precision type seldom exceeds 99 per cent.