Electroscope

n.

1.

(Physics) An instrument for detecting the presence of electricity, or changes in the electric state of bodies, or the species of electricity present, as by means of pith balls, and the like. Condensing electroscope (Physics) a form of electroscope in which an increase of sensibility is obtained by the use of a condenser.

Noun

1.

electroscope - measuring instrument that detects electric charge; two gold leaves diverge owing to repulsion of charges with like sign

measuring device, measuring instrument, measuring system