The thermocouple is element that is based on the principle of thermocouple-electricity. The thermocouple electricity principle states that when two different material conductors is connected to form two junctions and when electric current is applied on it to flow through both junction. Then each junction so heat exchange phenomenon. One junction is absorbing heat and other junction is releasing heat. Converse of this is also true i.e. when these two junctions is place in to different temperature then current starts flow through the conductor.