A galvanometer is an electromechanical instrument for detecting and measuring small electric currents, most commonly by the deflection of a magnetic needle or coil in the field the current produces. The earliest galvanometer was reported by Johann Schweigger at the University of Halle on 16 September 1820, shortly after Hans Christian Orsted's discovery that an electric current deflects a compass needle; Schweigger's multiplier wound the current-carrying wire in coils around the needle to amplify the effect. Michael Faraday relied on galvanometers to detect the induced currents in his experiments on electromagnetic induction.
Facts
Invented YearSourced to the subject's own account MeasuresSourced to the subject's own accountElectric current, by the mechanical deflection it produces in a magnetic needle or coil 1 Operating PrincipleSourced to the subject's own accountCurrent through a coil near a magnetized needle, or through a coil suspended in a fixed magnetic field, produces a torque proportional to the current; the resulting deflection, read against a calibrated scale, gives the current's size and direction. 1 ResolutionSourced to the subject's own accountD'Arsonval's original moving-coil galvanometer could detect currents as small as ten microamperes. 1 Operating RangeSourced to the subject's own accountA typical panel-meter galvanometer might read full scale at around 100 microamperes, with about 50 millivolts of voltage drop at that current. 1 Classification
Instrument ClassSourced to the subject's own accountMeasurement or Metrology Instrument 1 Connections
Invented By
Source Galvanometer (Wikipedia)
Used In
Sources
1. Galvanometer (Wikipedia)
WikipediaHistory section
The earliest galvanometer was reported by Johann Schweigger at the University of Halle on 16 September 1820.
D'Arsonval and Deprez section
d'Arsonval's initial instrument could detect ten microamperes.
Operation section
The basic sensitivity of a meter might be, for instance, 100 microamperes full scale (with a voltage drop of, say, 50 millivolts at full current).
Lede, instrument class
A galvanometer is an electromechanical instrument for detecting and measuring small electric currents, most commonly by the deflection of a magnetic needle or coil in the field the current produces.
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