Experimental Objective

To study the variation of the thermo electric E.M.F with temperature, for a Copper-Constantan thermocouple
 
 Working Principle

The experiment is based on the Seebeck effect, which states that when two dissimilar metals such as copper and constantan form a closed circuit and their junctions are maintained at different temperatures, a thermoelectric EMF is produced. The magnitude of the generated EMF depends on the temperature difference between the hot and cold junctions. By varying the temperature of one junction while keeping the other at a reference temperature, the corresponding thermoelectric EMF is measured. This establishes the relationship between EMF and temperature for a copper–constantan thermocouple.

A copper–constantan thermocouple consists of two dissimilar metallic wires joined at two junctions. When the junctions are maintained at different temperatures, a thermoelectric EMF is generated due to the Seebeck effect. For small temperature differences, the thermoelectric EMF varies approximately linearly with temperature. By measuring the EMF for different temperatures of the hot junction and plotting a graph of thermoelectric EMF versus temperature, the thermoelectric characteristics of the copper–constantan thermocouple are studied. This experiment is widely used to understand temperature measurement techniques and thermoelectric phenomena in thermal physics.