A T-type thermocouple works by passing electricity through the two wires. As the electricity flows through the wire, it creates a small amount of heat. If the two wires are similar in size, they will produce equal amounts of heat. However, if the two wires are different sizes, the larger wire will generate more heat than the smaller wire. By comparing the difference between the two wires, we can determine how much heat was generated.

• Outer protective sheath: heat-proof steel