Thermocouple is the most widely used temperature device in temperature measurement. Its main characteristics are wide kiss range, stable performance, simple structure, good dynamic response, and the ability to remotely transmit 4-20mA electrical signals for easy automatic control and concentration. control. The principle of thermocouple temperature measurement is based on the thermoelectric effect. Two different conductors or semiconductors are connected into a closed loop. When the temperature at the two junctions is different, a thermoelectric potential will be generated in the loop. This phenomenon is called the thermoelectric effect, also known as the Seebeck effect.
装配简单，更换方便压簧式感温元件，抗震性能好测量范围大机械强度高，耐压性 强。 The thermocouple is simple to assemble and easy to replace. The spring-loaded temperature-sensing element has good shock resistance. Large measuring range. High mechanical strength and high pressure resistance . Types of thermocouples Commonly used thermocouples can be divided into two categories, standard thermocouples and non-standard thermocouples . 谓 标准热电偶是指国家标准规定了其热电势与温度的关系、允许误差、并有统一的标准分度表的热电偶，它有与其配套的显示仪表可供选用。 The so-called standard thermocouple refers to the thermocouple whose national standard specifies the relationship between thermoelectric potential and temperature, the allowable error, and has a unified standard indexing table. It has a matching display instrument to choose from. Non-standardized thermocouples are inferior to standardized thermocouples in the scope or magnitude of use. Generally, there is no unified indexing table, which is mainly used for measurement in some special occasions. Standardized thermocouples in China Since January 1 , 1988 , all thermocouples and thermal resistors have been produced in accordance with IEC international standards, and S , B , E , K , R , J , T seven standardized thermocouples have been designated as China's unified design types. Thermocouple.
In order to ensure the reliable and stable operation of the thermocouple, the structural requirements of the thermocouple are as follows: ① The welding of the two thermal electrodes that make up the thermocouple must be firm; ② The two thermal electrodes should be well insulated from each other. To prevent short circuit; ③ The connection between the compensation wire and the free end of the thermocouple should be convenient and reliable; ④ The protective sleeve should ensure that the thermal electrode is fully isolated from the harmful medium.