Heat and Thermodynamics

2.2 General Theory of Thermometry

We have seen that the thermometric property depends on the temperature, and working of all types of thermometers is based on this principle.

Specifying the thermometric property by X, its variation with temperature (t) is generally represented by

 

X_t = X₀ (1 + αt + βt² + γt³ + ………)     (2.1)

 

where X_t = value of the thermometric property at t degree

         X₀ = value of the thermometric property at zero degree

α, β and γ are constants of a thermometric substance which are of rapidly decreasing order of magnitude. So, we may take

 

X_t = X₀(1 + αt)

 

and

 

X₁₀₀ = X₀(1 + α100)

 

or

 

 

or

 

 

By knowing ...