A Galvanometer is an electronic instrument used to measure and determine the direction of electric currents. This is done by means of mechanical effects produced by a current-carrying coil in a magnetic field. It is an electromechanical transducer producing a rotary deflection as a result of a electric current flowing through its coil.

The instrument is based upon a theory propounded by Hans C. Oersted, according to it, a magnetic needle is deflected by the presence of an electric current in a nearby conductor. When an electric current is made to pass through a conductor, the magnetic needle turns at right angles to the conductor so that its direction is parallel to the lines of induction around the conductor.

Galvanometers are generally the movable-coil type and are also known as d'Arsonval galvanometers, named after the French Physicist. Calibrated galvanometers are used in many electrical measuring devices. Ammeters are a kind of galvanometer which are used for measuring the current.

Use of Galvanometers

• Laser optical systems
• Educational laboratories