Thermocouple

A device made by joining two different metals together, and used to measure the temperature in a furnace.

It consists of two wires of different metals or alloys, joined together at one end and enclosed in a protective sleeve. The junction of the wires is placed at the temperature which needs measuring and the wires produce a small voltage which is proportional to the difference between the temperature to be measured and room temperature. From the voltage measured, the actual temperature can be determined. The combination of wires determines the voltage produced and the maximum operating temperature of the thermocouple.

See also control thermocouple, load thermocouple and probe thermocouple.