THERMOCOUPLES
TC Series 

THEORY AND CONSTRUCTION

A thermocouple consists of two wires, each made of a different metal, welded together at one end. 
When the welded point (measuring junction) is heated, a thermoelectronmotive force is produced that is porportional to the temperature difference between the welded point and the other end (reference junction). 
Therefore, by measuring this thermoelectronmotive force either with the reference junction temperature kept constant or by using an automatic compensation circuit, the measuring junction temperature can be measured.

The thermoelectromotive force of a thermocouple is independent of the diameter or length of the wire used and depends only on the type of wire used. 
The thermocouple is usually fitted in insulators and enclosed in a protecting tube with a terminal box and a mounting fitting attached.