This algorithm returns the saturation pressure as a function of Temperature: psat=psat(T). This type of vapor pressure equation was developed by W. Wagner. Because it cannot be solved for temperature analytically, the inverse function Tsat=Tsat(p) has to find Tsat iteratively.
function saturationPressure_T input Modelica.Units.SI.Temperature T; output Modelica.Units.SI.AbsolutePressure p; end saturationPressure_T;