In practice, alternatively to the volume of air, its mass is also indicated. Volume is established by dividing the mass m by the density . for accurate specification, one should always indicate also the appropriate density when stating mass. The density of air, in turn, depends on the temperature and the relative humidity.
Diagram 2.4.2.1
Using the values of diagram 2.4.2.1, the volume is derived from the mass of air. The diagram is based on 1 atmosphere = 736 Torr.
