A
multimeter or a
multitester, also known as a
VOM (Volt-Ohm meter or Volt-Ohm-milliammeter ), is an
electronic measuring instrument that combines several measurement functions in one unit. A typical multimeter can measure
voltage,
current, and
resistance.
Analog multimeters use a
microammeter with a moving pointer to display readings.
Digital multimeters (DMM, DVOM) have a numeric display, and may also show a graphical bar representing the measured value. Digital multimeters are now far more common but analog multimeters are still preferable in some cases, for example when monitoring a rapidly varying value.