Thermocouples

The thermocouple is a temperature sensor that provides a small millivolt signal that ranges between 10-80 mV. Thermocouples are made by connecting two dissimilar metals at one end to form a junction. The theory of operation of the thermocouple can be explained by the Seebeck effect, which was discovered by Thomas Seebeck in 1821. The amount of voltage that the thermocouple produces depends on the two types of metal that are used to form the junction. When Seebeck made this discovery in 1821, the thermocouple was not useful because the small amount of voltage that was produced in the millivolt range could not be amplified at the time.