Vapor quality

In thermodynamics, vapour quality is the mass fraction in a saturated mixture that is vapour; i.e. saturated vapour has a "quality" of 100%, and saturated liquid has a "quality" of 0%. Vapour quality is an intensive property which can be used in conjunction with other independent intensive properties to specify the thermodynamic state of the working fluid of a thermodynamic system. It has no meaning for substances which are not saturated mixtures (i.e., compressed liquids or superheated fluids).