IAPWS Releases, Supplementary Releases, Guidelines, and Advisory Notes

IAPWS provides recommended formulations for numerous properties of water, steam, and aqueous solutions. These fall in several categories:
Releases provide carefully evaluated, internationally agreed-upon data and formulations of properties for which measurements of high quality exist over a wide range of states. They are intended to embody the state of the art for representation of the property at the time of the Release.
Supplementary Releases provide supplementary material to an existing Release, or provide specific (perhaps simpler) formulations for a subset of the material in an existing Release. They are intended to be of the same quality as Releases.
Guidelines are similar, but for properties where the quality or range of the available data is limited. They are therefore not expected to provide as definitive a representation as Releases. Guidelines are expected to require revision when new information is available.
Advisory Notes are documents that give additional information and guidance that is intended to be useful for users of IAPWS property formulations.

A different type of IAPWS document is the IAPWS Certified Research Need (ICRN), which is a statement of the need for research on a specific topic. ICRNs are listed on a separate page.

An additional type of IAPWS document is the IAPWS Technical Guidance Document, giving international consensus guidelines on cycle chemistry for fossil and combined cycle power plants. Technical Guidance Documents are listed on a separate page.

All current IAPWS Releases, Supplementary Releases, Guidelines, and Advisory Notes are listed below and are downloadable as PDF files.
While IAPWS does not produce software, many IAPWS formulations have been implemented in software produced under the authority of the National Committees of IAPWS member countries; this page has links to these sources.
A separate document is available describing obsolete IAPWS recommendations that were issued in the past but are no longer current.


Supplementary Releases


Advisory Notes

This page updated January 10, 2017

iapws.org >> Releases, guidelines, etc.