The ceramic fine holes of armored thermocouples will fail if the components are sealed, and the method of electrostatic dust removal is often used to deal with it. However, the effect is not ideal, and it cannot be used in flammable and explosive environments. It can more accurately and quickly reflect the actual temperature of the measured end face, and is suitable for measuring the end face temperature of bearings and other machinery components. It is not only widely used in industrial temperature measurement, but also made into a standard reference instrument. It has accompanying display instruments available for selection.
Non standardized thermocouples are not as good as standardized thermocouples in terms of usage range or magnitude, and generally do not have a unified graduation table. They are mainly used for measurement in certain special occasions. The thermoelectric electromotive force is a single value function relationship with the working end temperature. The graduation tables for the temperature and thermoelectric electromotive force relationship of various thermocouples are made when the cold end temperature is zero. Therefore, special compensation wires are used to extend the cold end.
The main forms of failure are wire breakage and thermocouple breakage caused by vibration, and thermocouple short circuit or disconnection caused by bending.