Temperature dependence of the index of refraction of air

[cnunez12]

The index of refraction for a gas depends on temperature, as well as pressure. What is an experiment that would determine the temperature dependence of the index of refraction of air?

 

[DrDu]

The index of refraction of air is basically proportional to the density or concentration of air at fixed composition and furthermore depends on the water vapour content. The concentration is given by the ideal gas law as $c=n/V=p/RT$ while the saturation vapour pressure of water depends on temperature.