Voltmeter

Common card · No. 438328

A voltmeter is an electronic test instrument used for measuring electric potential difference between two points in an electric circuit. It is connected in parallel and typically has a high resistance so that it draws negligible current from the circuit. Analog voltmeters move a pointer across a scale in proportion to the voltage measured and can be built from a galvanometer and series resistor. Meters using amplifiers can measure tiny voltages of microvolts or less. Digital voltmeters give a numerical display of voltage by use of an analog-to-digital converter. Voltmeters are made in a wide range of styles, some separately powered (e.g. by battery), and others powered by the measured voltage source itself. Instruments permanently mounted in a panel are used to monitor generators or other fixed apparatus. Portable instruments, usually equipped to also measure current and resistance in the form of a multimeter are standard test instruments used in electrical and electronics work. Any measurement...

Read on Wikipedia · Image Hannes Grobe (talk), CC BY 3.0