The electric resistance pyrometer operates under the principle that an increase in temperature will cause an increase in the resistance to flow of an electric current

operates om the principle of temperature-induced resistance.

Explanation:

In physical quantities, the resistance of an electrical conductor can be correlated directly with the temperature of the material. The property for the change in the resistance with temperature is called the temperature coefficient of resistance. Mathematically, the resistance of a material is given as follows:

where R = conductor resistance at the temperature T.

Rreff = the conductor resistance at the reference temperature,

= temperature coefficient of resistance

T = Conductor temperature

Treff = reference temperature of the material.

From the equation, it can be seen that a positive coefficient for a material means an increase in the resistance of the material.

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