Thermocouple thermometer is a widely used temperature measuring instrument in the industry. It is made of thermoelectric phenomenon. 2 different metal wires are welded together to form working ends, and the other ends are connected with measuring instruments to form a circuit. The electromotive force occurs when the working end is placed at the working end at the measured temperature and the free temperature is different, so the current is passed through the loop. By measuring the temperature of the known place by the measurement of the electrical quantity, the temperature of another place can be measured.