Principle of operation

In 1821, the German–Estonian physicist Thomas Johann Seebeck apparent that back any aqueduct is subjected to a thermal gradient, it will accomplish a voltage. This is now accepted as the thermoelectric aftereffect or Seebeck effect. Any attack to admeasurement this voltage necessarily involves abutting addition aqueduct to the "hot" end. This added aqueduct will again additionally acquaintance the temperature gradient, and advance a voltage of its own which will argue the original. Fortunately, the consequence of the aftereffect depends on the metal in use. Using a antithetical metal to complete the ambit creates a ambit in which the two legs accomplish altered voltages, abrogation a baby aberration in voltage accessible for measurement. That aberration increases with temperature, and is amid 1 and 70 microvolts per amount Celsius (µV/°C) for accepted metal combinations

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The voltage is not generated at the alliance of the two metals of the thermocouple but rather forth that allocation of the breadth of the two antithetical metals that is subjected to a temperature gradient. Because both lengths of antithetical metals

acquaintance the aforementioned temperature gradient, the end aftereffect is a altitude of the temperature at the thermocouple junction.