Joule-Thomson effect: defined

The Joule-Thomson effect is a measure of the deviation of the behavior of a real gas from what is defined to be ideal-gas behavior. In this experiment a simple technique for measuring this effect will be applied to a few common gases. 

It is necessary to define the conception of the inversion temperature a little more closely. In the literature of the subject we find this term used with two distinct meanings first, as the temperature at which the Joule-Thomson effect vanishes when the gas is allowed to expand from a high pressure p to the pressure of the atmosphere, and, secondly, as the tempera-... 

However, the key quantity in the context of the. Joule-Thomson effect is the expansivity defined in Eq. (5.132). From the thermodynamic definition and the statistical phy.sical Eqs. (5.197) and (5.198), it is immediately clear that... 

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