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Guideline on a Low-Temperature Extension of the IAPWS-95 Formulation for Water Vapor
October 2012

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This Guideline provides a low-temperature extension of the ideal-gas equation used in the IAPWS Formulation 1995 for the Thermodynamic Formulation of Ordinary Water Substance for General and Scientific Use. This allows IAPWS-95 to be used for vapors at temperatures as low as 50 K (compared to the original limit of 130 K).

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 Guideline is the product of the Working Group "Thermophysical Properties of Water and Steam" (TPWS) and the Subcommittee on Seawater (SCSW) of the International Association for the Properties of Water and Steam (IAPWS).

This page updated September 21, 2016

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