|voltmeter (vōlt'mē'tər) Pronunciation Key
An instrument used for measuring the difference in voltage between two points in an electric circuit. Voltmeters typically make use of an ammeter that measures current flow across a known resistance inside the voltmeter; direct-current voltages can then be determined by Ohm's law. Digital voltmeters employ A/D converters to provide the numerical value of the voltage displayed. Compare ohmmeter.