Thermocouple is a commonly used temperature measuring element in temperature measurement instruments. It directly measures temperature and converts the temperature signal into a thermoelectric electromotive force signal, which is then converted into the temperature of the measured medium through electrical instruments (secondary instruments). The appearance of various thermocouples is often very different due to needs, but their basic structure is generally the same. They are usually composed of main parts such as thermal electrodes, insulation sleeve protection tubes, and junction boxes, and are usually used in conjunction with display instruments, recording instruments, and electronic regulators.

