Thermistor is made using semiconductor heat-sensitive resistance. In the telecommunications and automatic control system, and used to make a thermometer. Commonly used in low temperature zone thermocouple is a kind of temperature detector. Its main characteristic is high accuracy, stable performance. The platinum thermocouple measuring accuracy is high, it is not only widely used in industrial temperature measurement, and is made into standard benchmark instrument. Thermocouple temperature measuring thermocouple temperature measurement principle and the material is based on the metal conductor resistance value increases with the increase of the temperature of the properties for temperature measurement. Thermocouples are mostly made of pure metal materials, the application is a lot of platinum and copper, in addition, now began to use the materials such as nickel, manganese and rhodium thermocouple.