Mumbai University > Electronics and Telecommunication > Sem3 > Electronic Instruments and Measurements

Marks: 10M

Year: Jun15, Dec14, Dec13

Working –

• The input signal to be analyzed is heterodyned to a higher IF by an internal local oscillator

• Tuning the local oscillator shifts various signal frequency components into the pass band of the IF amplifier

• The output of the IF amplifier is rectified and is applied to the metering circuit. The instrument using the heterodyning principle is called a heterodyning tuned voltmeter

• The operating frequency range of this instrument is from 10 kHz to 18 MHz in 18 overlapping bands selected by the frequency range control of the local oscillator. The bandwidth is controlled by an active filter and can be selected at 200, 1000, and 3000 Hz.

Applications of Heterodyne Wave Analyzer –

They are primarily used in electrical, sounds, and vibration measurements.

In industries, there are heavy machineries which produce a lot of sound and vibrations. It is very important to determine the amount of sound and vibrations because if it exceeds the permissible level it would create a number of problems. The source of noise and vibrations is first identified by wave analyzer and then it is reduced by further circuitry.

A fine spectrum analysis with the wave analyzer shows various discrete frequencies and resonances that can be related to the motion of machines.