Thermocouple is composed of a pair of conductors which use different materials and be connected at one end. And as part of the circuit of temperature which are measured by thermoelectric effect. The thermoelectric power produced while the temperature on measuring end and free end difference, the instrument will show the corresponding temperature value of thermoelectric power.The resistance value will change with the temperature. So the thermal resistance measure its temperature according to this theory. When the resistance changes, the instrument will show the value of the temperature.It usually be used with display instrument, recording instrument and PC systems.It can measure the temperature(-200℃~1000℃) of solid, liquid, gas and surface in different produce process.Feature：High mechanical strength, good pressure resistanceSmall thermal inertia, fast response timeHigh measure precisionGood seismic performanceSimple construction for application, installation and maintenance measurement range and tolerance