Description of thermocouple: When a metal's temperature changes, its electrons move faster. When the speed of the electrons differs in the two metals connected to each other in the thermocouple, the electrons interfere with each other where the two metals meet. Here there is an excess of electrons on one side, and a lack of electrons on the other.

This difference generates an electric current related to the type of the two metals on the one hand, and heat on the other. This current is called the electro-thermal current. These two currents are connected to an electronic board where the difference between the two currents is measured in “microvolts” based on a temperature difference of one Kelvin. The value of the electro-thermal current is in microvolts for every 1 Kelvin difference in temperature.