FAQ00634 of Temperature Controllers FAQ

Thermocouple temperature sensors are constructed using two dissimilar metals that are joined together. The junctions are called the measuring junction and the reference junction (output terminal side). A thermoelectromotive force is generated between the junctions with a fixed correlation to the temperature providing the difference in temperature.

Therefore, the temperature at the measuring junction can be determined from the thermoelectromotive force when a fixed temperature is maintained at the reference junction.

Thermocouple temperature sensors are capable of measuring the highest temperatures among contact temperature sensors by using this measurement method.