Is a temperature sensitive element, and is a primary instrument, thermocouple measuring temperature directly. Composed of 2 different conductor materials composed of closed-loop, due to different materials, different electron densities produce electron diffusion, stable equilibrium is created the EMF. When the gradient of temperature, current in the circuit, thermoelectric, the greater the temperature difference, greater the currents there. The measured thermoelectric temperature value then you can know. Thermocouple is actually an energy converter that can convert thermal energy into electrical energy.
Thermocouple technical advantages: wide range of thermocouple and performance compared to stable high measurement accuracy, thermocouple direct contact with the object being measured, not under the influence of medium heat faster response time, thermocouples to temperature change response flexible measuring range, continuous temperature measurement of thermoelectric couple from -40~+ 1600 c can be; thermocouple properties, and good mechanical strength. Use long life devices.