Definition of: variometer

(vâr′ē·om′ə·tər) noun Electr.
1. An instrument used to determine the variation of magnetic force at different times or at different places, usually by means of a needle suspended within the magnetic field.
2. A variable inductance device composed of two coils connected in series, one of which revolves within the other, and capable of controlling the strength of a current. [<VARIO- + -METER]