True R.M.S Voltmeter Working and Theory

In this instrument one amplifier first amplifies the input signal. Then it fads the amplified signal into the directly heated filament of a vacuum diode. The filament should have small thermal time constant to respond … Read more

Electronic Voltmeter Types of Electronic Voltmeter

Electronic voltmeters use rectifiers, amplifiers and other circuit elements to produce a current. And this current is proportional to the voltage to be measure. A conventional voltmeter takes a non negligeable current from the circuit … Read more

Mechanical Resonance Frequency Meter

Mechanical Resonance Frequency Meter (Vibrating Reed)

Mechanical resonance type frequency meter is principally an electro-mechanical device. Also, we call this instrument the vibrating reed type frequency meter. Conceptually, the principal of this frequency meter is quite simple. The instrument consists of … Read more