The working principle of thermal resistance/thermocouple

1. What is the measurement principle of thermocouples?

The working principle of a thermocouple is based on the Seeback effect, that is, two ends of conductors of two different components are connected into a loop. If the two connection ends have different temperatures, a physical phenomenon of thermal current is generated in the loop.

A thermocouple consists of two different wires (hot electrodes), one end of which is welded to each other to form the measuring end (also called the working end) of the thermocouple. Insert it into the medium of the temperature to be measured; the other end of the thermocouple (reference end or free end) is connected to the display instrument. If there is a temperature difference between the measuring end and the reference end of the thermocouple, the display meter will indicate the thermoelectromotive force generated by the thermocouple.

2. What is the measurement principle of thermal resistance?

The thermal resistance measures the temperature by using the characteristic that the resistance of the metal conductor or semiconductor changes as the temperature changes. The heated part (temperature sensing element) of the thermal resistance is a skeleton made of thin metal wires evenly wound around the insulating material. The substrate is formed on or by a laser sputtering process. When the measured medium has a temperature gradient, the measured temperature is the average temperature of the medium layer in the range where the temperature sensing element is located.