## Preface

The international research regarding the thermophysical properties of water and steam has been

coordinated by the International Association for the Properties of Water and Steam (IAPWS).

IAPWS is responsible for the international standards for thermophysical properties. These

standards and recommendations are given in the form of releases, guidelines, and advisory

notes. In 1997, IAPWS adopted the Release “IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam” called IAPWS-IF97 for short.

The first edition of this book, published in 1998, described IAPWS-IF97 as it was adopted by

IAPWS in 1997. In 2008, the second edition was published. Apart from incorporating all the

“supplementary” backward equations developed after the adoption of IAPWS-IF97, it was a

significant extension of the first edition; for details see the preface to the second edition.

In the third edition, apart from some printing errors, the following changes have been made.

In Part A, all revisions of the Releases and Supplementary Releases adopted after 2008 were

taken into account. In connection with the basic equations, equations for calculating the relative

pressure coefficient and the isothermal stress coefficient and thus the corresponding partial

derivatives have been included. The most important change is the incorporation of the current

equation of the thermal conductivity of water and steam adopted by IAPWS in 2011. In Part B,

the tables of the thermal conductivity and the Prandtl number that contains the thermal conductivity have been recalculated. Further changes are the (partly significant) reduction of the

sizes of the tables combined with adding seven new tables of properties that were not yet considered in the second edition. In Part C, the diagram for the thermal conductivity is recalculated

due to the new equation for this property. Because of the thermal conductivity, the diagrams for

the quantities Prandtl number and thermal diffusivity, had also to be recalculated.

The Parts D (IAPWS-IF97 Electronic Steam Tables on CD-ROM) and E (Wall Charts of the

Properties of Water and Steam) of the second edition were omitted. However, information how

to calculate property values for water and steam online and how to obtain copies of coloured

wall charts of the Mollier h-s diagram, the T-s diagram, and the log(p)-h diagram are given at

www.international-steam-tables.com. In addition, there is also information on propertycalculation software for Windows and Linux applications and for IOS and Android smart

phones, tablets, and pocket calculators.

We are grateful to the members of the IAPWS Working Groups “Thermophysical Properties

of Water and Steam” and “Industrial Requirements and Solutions” for fruitful discussions. Our

warmest thanks are dedicated to Dr. M. Kunick and Dr. S. Herrmann for formatting the text of

Part A and the tables as Microsoft Excel sheets for Part B, and for their help in revising the

pressure-temperature diagrams in Part C of the book. We thank Mr. M. Sünder for reprogramming all of the equations and tables in Parts A and B of the book. We would also like to thank

Mrs. R. Gölzenleuchter very much for producing all of the figures.