In 1820, Danish physicist, Hans Christian Oersted noted that a magnetic needle gets deflected as it comes in contact with an electric current. This observation eventually became the basic principle of the working of a galvanometer. In the same year, German physicist, Johann Schweigger worked on this principle and came up with the first galvanometer. The credit for the invention of the first moving-coil galvanometer, which is widely used even today, goes to the French physicist, Jacques Arsene D'Arsonval. A few years later, Edward Weston made quite a few changes to this design and improvised it.
The galvanometer works on the basis of electromechanical transduction, which responds to the current that it is subjected to on the basis of the strength of the current and its rate of flow. Other than these two factors, it also responds to any sort of stimuli, which strengthens the current, or blockage, which weakens the current. Among the various types of galvanometers, the two most commonly used ones are ...
- ▶ Moving-coil galvanometer with the coil either mounted on pivots or suspended by thin metal strips.
- ▶ Moving-magnet galvanometer with the needle mounted on the pivot in itself being a permanent magnet surrounded by the coil.
Galvanometers have been in use since the 19th century. Even though modern technology has introduced several such devices which overshadow this device in certain aspects, it still remains one of the most-preferred choice when it comes to detection or measuring electric current flowing from and to a source.