Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

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 third edition cancels and replaces the second edition (ISO 6143:2001), which has been technically revised.

The main changes are as follows:

— update of definitions, in particular those taken from the VIM;
— update of the bibliography and the corresponding references in the text;
— update of the information in Annex C on the computer programme B_LEAST; information on alternative software (Annex D);
— amendment of 6.2 (now 7.2) “Comparison of several calibration gas mixtures” and related statements in other parts of the document
— amendment of the recommendations concerning the number of replicate measurements per sample;
— revision of the requirements for the report of results (“Test report”);
— new Annex D (informative) “Additional information on data evaluation”;
— deletion of A.1 “Uncertainty specifications for reference gas mixtures”;
— additional references to relevant ISO standards (ISO 12963, ISO 14912, ISO 15796);
— correction of Formula (4) for the power functions.
— recommendation added to Annexes B and C not to use B_LEAST for evaluations using the exponential function (due to recently demonstrated errors) or to calculate the parameter uncertainties (standard uncertainties and covariances) separately.

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 6143:2025

Gas analysis. Comparison methods for determining and checking the composition of calibration gas mixtures

Current

Published:

30 Jun 2025