Ammeter
Videos
An ammeter is an instrument used to measure the current in a circuit. Electric currents are measured in amperes, hence the name. For direct measurement, the ammeter is connected in series with the cir
Demonstration model of a moving iron ammeter. As the current through the coil increases, the plunger is drawn further into the coil and the pointer deflects to the right.
Ammeter from the University of Dundee Physics Department
Ammeter from the old New York Penn Station terminal service plant in New York City
Face of an older moving iron ammeter with its characteristic non-linear scale. The moving iron ammeter symbol is in the lower-left corner of the meter face.
Galvanometer
Videos
A galvanometer is an electromechanical measuring instrument for electric current. Early galvanometers were uncalibrated, but improved versions, called ammeters, were calibrated and could measure the f
An early D'Arsonval galvanometer showing magnet and rotating coil
Close-up view (rear) of a permanent magnet type moving coil meter
Closed-loop galvanometer-driven laser scanning mirror
A galvanometer mechanism (center part), used in an automatic exposure unit of an 8 mm film camera, together with a photoresistor (seen in the hole on top of the leftpart).