A multimeter or a multitester,
also known as a VOM (Volt-Ohm meter),
is an electronic measuring instrument that combines several measurement
functions in one unit.
This multimeter includes basic features such as the ability to
measure voltage, current, and resistance.

Digital multimeters (DMM, DVOM) display the measured value in numerals,
and may also display a bar of a length proportional to
the quantity being measured.

A multimeter can be a handheld device useful for basic fault
finding and field service work,
or a bench instrument which can measure to a very high degree of accuracy.

They can be used to troubleshoot electrical problems in
a wide array of industrial and household devices such as
electronic equipment, motor controls, domestic appliances,
power supplies, and wiring systems.