Developed by Russian National Committee (RNC) of
International Association for the Properties of Water and Steam (IAPWS).
This calculation page is based on the
"Guideline on the Henry’s Constant and Vapor-Liquid Distribution Constant for Gases in H2O and D2O at High Temperatures" 
provided by IAPWS.
Detailed information about used equations, constants, range of validity etc is presented in PDF version of IAPWS Release which can be downloaded from IAPWS web site www.iapws.org