What are thermocouples made from?

Thermocouples are devices used to measure temperature by utilizing the thermoelectric effect, specifically the Seebeck effect. They consist of two dissimilar metals joined at one end. When there is a temperature difference between the joined end (the measuring junction) and the other ends of the two metals, it generates a voltage that can be correlated to the temperature difference. The use of two different metals is essential for creating this voltage; if the metals were similar, no significant voltage would be produced, making it impossible to measure temperature effectively.

The selection of specific metal combinations affects the range of temperatures that can be measured and the sensitivity of the thermocouple, reinforcing the importance of having dissimilar metals in their construction. Each combination of metals has unique characteristics that make them suitable for particular temperature ranges and applications in various industries.