An Electronic Voltmeter is an instrument used to measure the voltage between two points in a circuit. It also measures differences of electric potential in volts or units that are fractions or multiples of volts. The instrument is generally combined with an ammeter and an ohmmeter in a multipurpose instrument. Most voltmeters are analog types and based on a galvanometer.

A voltmeter is also considered to be a very high resistance ammeter, this is so because the voltage is measured by allowing it to pass through a current and a resistance.

Types of Electronic Voltmeter

• Analog Voltmeter: These instruments give voltage readings that vary over a continuous range as indicated by a scale and pointer.
• Digital Voltmeter: These instruments are gaining popularity because they provide voltage readings that are composed of a group of digits.
• Vacuum Tube Voltmeter: This electronic voltmeter uses a tube or valve circuit to amplify the input voltage. It is used to increase the sensitivity, and increase the input impedance.
• Oscilloscope: It is also sometimes considered a voltmeter because it is capable of giving a calibrated visual indication of voltage.

Good voltmeters are known to have infinite input impedance; these instruments have no effect on the circuit being measured. Real voltmeters have limited impedance, which is designed to make it as high as possible. The sensitivity of a voltmeter is usually specified in ohms / volt.

Use of Voltmeters
Voltmeters are important measuring instruments used in various fields and areas. Some of the important areas are:

• Laboratory Instruments
• Electrical Testing
• Educational Lab Instruments