Foreword

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This document was prepared by Technical Committee ISO/TC 158, Analysis of gases, in collaboration with the European Committee for Standardization (CEN) Technical Committee CEN/TC 238, Test gases, test pressures, appliance categories and gas appliance types, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).

This second edition cancels and replaces the first edition (ISO 14912:2003 and ISO 14912:2003/Cor.1:2006), which has been technically revised.

The main changes are as follows:

— update of the molar mass data for mixture components in Annex C according to the 2019 to 2021 IUPAC/CIAAW atomic mass data;
— update of the value of the gas constant according to the 2018 revision of the International System of Units (SI);
— update of the bibliography and the corresponding references in the text;
— update of the information in Annex E on the computer programme CONVERT;
— correction of Formulae (37) and (39);
— recalculation of the examples in Annex D;
— addition of a table of molar mass data for the relevant elements from which the molar mass data for mixture components were calculated;
— addition of information concerning data for synthetic air;
— editorial corrections.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

BS EN ISO 14912:2025

Gas analysis. Conversion of gas mixture composition data

Current

Published:

31 May 2025