ELECTROMETER
electrometer
(noun) meter to measure electrostatic voltage differences; draws no current from the source
Source: WordNet® 3.1
Etymology
Noun
electrometer (plural electrometers)
A device used to detect and measure static electricity; an electroscope.
A precision voltmeter that draws almost no current from the circuit.
Source: Wiktionary
E`lec*trom"e*ter, n. Etym: [Electro- + -meter: cf. F. électromètre.]
(Physics)
Definition: An instrument for measuring the quantity or intensity of
electricity; also, sometimes, and less properly, applied to an
instrument which indicates the presence of electricity (usually
called an electroscope). Balance electrometer. See under Balance.
Source: Webster’s Unabridged Dictionary 1913 Edition