What is a Galvanometer?

As a device for creating accurate measurements, the galvanometer has been with us since the early 19th century. While not the latest in technology, there are still a number of devices that utilize galvanometer technology to measure electricity in a number of settings. Here is some background on the galvanometer, as well as some examples of how the instrument has been used through the years.

As a form of ammeter, the galvanometer is a device that is all about taking accurate measurements. While different types of ammeters will measure various sorts of energy, the purpose of the galvanometer is focused on measuring electric current in both the body and in manufacturing and agricultural settings.

Driving its name for Luigi Galvani, who is said to have designed the first prototype of the instrument, the galvanometer is more usually associated with William Thomason, who experimented with the unit to expand the number of common uses for the device. Johann Schweigger noted his work at the University of Halle in 1820. There is also evidence that Andre-Marie Ampere also added to the development of the galvanometer in the early years.

The basic use of the galvanometer is to measure direct electric current as it flows to and from a source. Being essentially an electromechanical transducer, the galvanometer responds to the current in three ways: it’s strength, rate of flow and reaction to any type of stimuli or blockage that seems to weaken or strengthen the current. Well into the 20th century, the galvanometer was an essential tool in any laboratory that worked with electricity and sought new ways to safely contain and utilize electrical current for production of goods and travel.

Communications were also positively impacted by the use of galvanometers. In particular, the mirror galvanometer, which used a mirror in place of a metal pointer, proved to be ideal for use as receivers in telegraph systems, both domestic and trans-Atlantic. In the medical field, galvanometers were used for years to help position the pens that record results during an electrocardiogram. Law enforcement also benefited from the creation of the galvanometer, as the device moved the pens along on lie detectors machinery, providing a record of the subject’s reactions to different questions.

While technology has eclipsed some of the earlier uses of the galvanometer, the instrument is far from obsolete. Mirror galvanometers are still in high demand, working as beam positioning equipment in laser optical systems. Teachers still use old-fashioned galvanometers to teach about electrical current and properties. While the use of the galvanometer may be more specialized than in years past, the device will likely be a useful part of a number of pursuits for many years to come.