The electromotive force (EMF) is composed of two parts: one is the contact EMF between two conductors, and the other is the temperature difference EMF of a single conductor. In temperature measurement, thermocouples are widely used due to their many advantages such as simple structure, ease of manufacturing, broad measurement range, high accuracy, low inertia, and easy signal transmission over long distances. Additionally, as thermocouples are passive sensors, they do not require an external power source for measurement, making them very convenient to use. Therefore, they are often employed to measure the temperature of gases or liquids inside furnaces and pipes, as well as the surface temperature of solids.