Thermocouple and the thermocouple, belong to the same contact temperature measurement of temperature measurement, are often are used in the field of industrial temperature sensors. Although the role of the same are measuring the temperature of the object, but the principle and characteristics of them are different. Thermocouple and thermocouple have what difference: the working principle of thermocouple, thermocouple temperature measurement is widely used in the temperature of the device, it is the main characteristic of measuring temperature range is wide, temperature performance is stable, and its simple structure, good dynamic response, pass 4 - far more 20 ma electrical signals to facilitate automatic control and centralized control. Thermocouple temperature measurement principle is based on thermoelectric effect. Connect the two different conductor or semiconductor into closed loops, when the two contacts in temperature is not at the same time, the circuit will produce thermoelectric potential, this kind of phenomenon called the thermoelectric effect, also known as the seebeck effect. Closed loop of the thermoelectric potential consists of two kinds of potential 'thermoelectric potential' and 'contact potential'. The working principle of thermocouple, thermocouple is widely applied in industry, but because of the thermocouple temperature measurement range makes it application by certain restrictions, thermocouple and the thermocouple, belong to the same contact temperature measurement of temperature measurement, are often are used in the field of industrial temperature sensors. Although the role of the same are measuring the temperature of the object, but the principle and characteristics of them are different.