Basically, one of the most important tools in various fields of electronic and telecommunications systems applied to frequency meters. This tool can be implemented as analog or digital. Importantly, the implementation of this instrument considering the location and the desired frequency range. Frequency meter to display the frequency of a periodic signal. There are different types, some of which frequency meters to measure low frequencies up to 900 kHz are used.This device serves to balance the two opposing forces and changes in the frequency, due to changes in the balance, can be demonstrated by measuring the deflection of a needle on a scale. It has two coils that are tuned to different frequencies and the ability to move the needle.