An Ohmmeter is an electrical measuring instrument that is used to measure electrical resistance, which is the opposition produced to the flow of an electric current. It can also be used to measure the electrical resistance of a conductor.

Salient Features

• A meter generally includes a voltmeter; and often an ammeter.
• In general usage, the instrument operates by using the voltmeter to measure a voltage drop and then converting the reading into a corresponding resistance reading.
• The resistance reading is indicated through a mechanical meter movement that operates on electric current.
• In most cases, a meter is supplied with an internal source of voltage to produce the necessary current to operate the movement, and also appropriate ranging resistors to allow just the right amount of current through the movement at any given resistance.

Megohm meter is special type of ohmmeter used for measuring very high resistances.

Application

This is used for various purposes. Some of areas where it finds application are:

• Precision measurement of Resistors
• High volume production testing
• Laser trimmers
• Thermoelectric coolers
• Connectors
• Fine wire switches
• Thermistors
• Low-inductance, resistive devices
• Electrical equipments