What is a Thermocouple Junction?

Thermocouple junction is the measuring point of a thermocouple sensor, where the positive and negative legs of the thermocouple wire are welded together. Thermocouples are formed from two dissimilar electrical conducting wires, joining these creates the thermocouple junction which utilises a phenomenon called the Seebeck effect to measure temperature. It can sometimes be called the Hot end junction, but this is a more general term.