Thermocouples are the most widely used and versatile devices that are used to measure the temperature. They convert the units of heat into usable engineering
units that serve as input signals into process controllers and recorders. A thermocouple is made up of two dissimilar metals, joined together at one end,
that produce a voltage with a change in temperature. The junction of the two metals, called the sensing junction, is connected to extension wires.
The voltage appears across the free ends of the thermocouple wires, where it is measured and converted into units of heat calibration.