The application of thermocouple is very extensive. The structure characteristics of the thermocouple: ( 1) End thermocouple: end thermocouple temperature components made by special processing of the resistance wire, close to the face in the thermometer. Compared with general axial thermocouple, it can reflect more correctly and quickly measured end face of the actual temperature, suitable for measuring the surface temperature. ( 2) Wz series thermocouple assembly: usually by the temperature sensing element, main parts, such as installing fixtures and connection box with high measuring accuracy, stable and reliable performance, etc. Practice with pt100 platinum thermocouple is most widely used. ( 3) Flame-proof thermocouple, flame-proof thermocouple through the special structure of the junction box, the box inner explosive mixed gas by affected by sparks or electric arc explosion limit within the junction box, production site won't explode. ( 4) WZPK platinum thermocouple, thermocouple is by the thermal components, wire, insulation materials, stainless steel casing combination solid body, it has the following advantages: slender shape, heat fast response time, vibration resistance, long service life, etc.