galvanometer

noun

1. an instrument for detecting the existence of small electric currents and determining their strength.

noun

1. any sensitive instrument for detecting or measuring small electric currents

n.

1802, from comb. form of galvanism + -meter.

1. An instrument that detects small electric currents and indicates their direction and relative strength. Current flowing through the galvanometer passes through a coil near a magnetized needle on a pivot; the strength of the current in the coil regulates the strength of a magnetic field that displaces the needle. Galvanometers can be used directly as ammeters, and are the core element of many ohmmeters and voltmeters.