Introduce the difference between thermocouple and thermal resistance

explained by the relevant personnel of Jiangsu Huanya electric heating instrument Co., Ltd. At present, there is a standard specification for thermocouples used in the world. According to the international regulations, thermocouples are divided into eight different gradations, namely B, R, s, K, N, e, J and t. The minimum temperature can be 270 ℃ below zero, and the maximum temperature can be 1800 ℃. B, R and s belong to platinum series thermocouples. Because platinum is a precious metal, the temperature can be measured by the thermocouple, So they are also called precious metal thermocouples, and the rest are called cheap metal thermocouples. There are two types of thermocouple structure, common type and armored type. ordinary thermocouple is generally composed of hot electrode, insulating tube, protective sleeve and junction box, while armored thermocouple is a solid combination of thermocouple wire, insulating material and metal protective sleeve after stretching. But the electrical signal of thermocouple needs a special wire to transmit, which we call compensation wire. different thermocouples need different compensation wires. Its main function is to connect with the thermocouple to keep the reference end of the thermocouple away from the power supply, so as to stabilize the temperature of the reference end. compensation wire is divided into compensation type and extension type. The chemical composition of extension wire is the same as that of thermocouple to be compensated. However, in practice, extension wire is not made of metal with the same material as thermocouple.