This guideline provides an equation of state (in the form of a Gibbs energy function) for the thermodynamic properties of cold and supercooled (metastable) liquid H2O.
The range of validity is the metastable liquid from the homogeneous ice nucleation temperature to the melting temperature at pressures from 0 MPa to 400 MPa. The equation is also valid for stable liquid states up to 300 K in the same pressure range, where IAPWS-95 remains the recommended formulation.
The development of the formulation and comparisons to available data are described in detail in a scientific article.
The Russian National Committee of IAPWS (through Moscow Power Engineering Institute) has provided an online calculation page, which may be useful in program development and verification. Note that IAPWS is not responsible for the content of these online calculation pages.
This Guideline is the product of the Working Groups "Thermophysical Properties of Water and Steam" (TPWS) and "Subcommittee on Seawater" (SCSW) of the International Association for the Properties of Water and Steam (IAPWS).
This page updated May 29, 2018