Thermocouple temperature measurement is used in common - the temperature of the device Shanghai dragon instrument electric appliance co. , LTD

First of all, the temperature of the thermocouple is applied widely in temperature measurement devices, his main characteristic is the wide range of measuring kiss, compare with stable performance, simple structure at the same time, the dynamic response is good, can far eastone 4 - more 20 ma electrical signals to facilitate automatic control and centralized control. Thermocouple temperature measurement principle is based on thermoelectric effect. Two different conductors or semiconductor cohesion 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. There are two kinds of closed loop of thermoelectric potential of electric potential; The thermoelectric potential and contact potential. The ends of the conductor temperature potential refers to the same potential, because of the different temperature of different conductors with different electron density, so they produced by electric potential is not the same, the contact potential peer is refers to the two different conductor in contact. Due to their different degree of electron dense so produce certain electron diffusion, when they reach a certain equilibrium of electric potential and contact potential depends on the size of the two different conductor material properties and their temperature contact point. At present the application of thermocouple on the international has a standard, the international rules on the thermocouple is divided into eight different degree, respectively B, R, S, K, N, E, J and T, the measurement of low measurable temperature of minus 270 degrees Celsius, up to 1800 degrees Celsius. B, R, S belong to platinum series thermocouple, because platinum are precious metals, so they are also known as precious metal thermocouple and the remaining few called cheap metal thermocouple. Thermocouple junction structure has two kinds, ordinary type and armoured. Normal sexual thermocouple normal by hot electrode, insulation tube, maintenance of casing and junction box, etc, and armoured thermocouple type is the thermocouple wire, insulation materials and metal casing maintenance three combination after assembly, after stretching processing from a combination of a solid.