To process this page used the WaterSteamPro function "wspDDDHPPH": derivate of density on enthalpy with constant pressure of water/steam [kg·sec2/m5] as function of pressure p [Pa], specific enthalpy h [J/kg].
The range of the validity is within that described in IF-97. The function wspWATERSTATEAREAPH is used to determine the IF-97 region. Then the necessary function (wspTxPH) is used. Since at some stages the function use iterations, to speed up calculations you may disable precision mode (functions wspGETTOLERANCEMODE and wspSETTOLERANCEMODE) or vary relative precision for internal iterations (functions wspGETTOLERANCE and wspSETTOLERANCE).
WaterSteamPro is a registered trademark of Moscow Power Engineering Institute (Technical University).
Copyright (c) MPEI (TU), 1999-2010.
Copyright (c) Konstantin A. Orlov, 1999-2010.