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IAPWS R10-06(2009)
Revised Release on the Equation of State 2006 for H2O Ice Ih
September 2009

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This formulation is recommended for the calculation of thermodynamic properties of ordinary water in its solid hexagonal phase I, including vapor-solid and liquid-solid equilibria in conjuction with the IAPWS-95 formulation for thermodynamic properties of fluid water for general and scientific use.
The formulation is for the Gibbs energy as a function of temperature and pressure; appropriate combinations of derivatives can produce any thermodynamic property desired (density or specific volume, sound speed, heat capacity, enthalpy, entropy, etc.).
The formulation is valid in the entire region of stable existence of ice Ih. It extrapolates in a physically reasonable way outside this region.
The development of the formulation and comparisons to available data are described in detail in a scientific article.

Software Implementation
The IAPWS Subcommittee on Seawater, in cooperation with the SCOR/IAPSO Working Group 127, developed the "Thermodynamic Equation of Seawater 2010" (TEOS-10) which was endorsed as an international standard for oceanography by UNESCO-IOC in 2009 and by IUGG in 2011. The open-source code of TEOS-10 includes software implementations of this IAPWS formulation. Note that IAPWS is not responsible for the content of these external pages.

Revision History

This Release is the product of the Working Group "Thermophysical Properties of Water and Steam" (TPWS) of the International Association for the Properties of Water and Steam (IAPWS).

This page updated May 29, 2018

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