Absolute humidity per unit mass of moist air at saturation is computed from pressure and temperature in the state record. Note, that unlike X_sat in the BaseProperties model this mass fraction refers to mass of moist air at saturation.
function Xsaturation
extends Modelica.Icons.Function;
input ThermodynamicState state "Thermodynamic state record";
output MassFraction X_sat "Steam mass fraction of sat. boundary";
end Xsaturation;