National foreword

This British Standard is the UK implementation of ISO 625:2025.

The UK participation in its preparation was entrusted to Technical Committee W/-, Miscellaneous Standards.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2025.

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 27, Coal and coke, Subcommittee SC 5, Methods of analysis.

This third edition cancels and replaces the second edition (ISO 625:1996), which has been technically revised. It also incorporates the Technical Corrigendum ISO 625:1996/Cor. 1:1996.

The main changes are as follows:

the normative references have been updated;
the mandatory terms and definitions clause (Clause 3) has been added and subsequent clauses have been renumbered;
Clause 5 has been updated;
Figures 1, 2, 3 and 4 have been updated;
Clause 9 has been updated;
Clause 11 has been revised;
the test report has been updated;
Annex A has been revised.

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.

Introduction

An alternative method to the one specified in this document is given in ISO 609.

1 Scope

This document specifies a method of determining the total carbon and the total hydrogen in coal and coke, by the Liebig method.

2 Normative references

3 Terms and definitions

4 Principle

5 Reagents and materials

5.1

5.2

5.3

5.4

5.5

5.6

5.7

5.8

5.9 Glass wool.

5.10

5.11

5.12

6 Apparatus

6.1

6.2

6.3 Combustion assembly

6.4

6.5

6.6

6.7

6.8

6.9

6.10

6.11

7 Preparation of the apparatus

7.1 Preparation of the combustion tube

7.2 Conditioning of the combustion tube

7.3 Conditioning of the absorption train

8 Preparation of test sample

9 Procedure

10 Blank test

11 Expression of results

11.1 Total carbon

11.2 Organic carbon

11.3 Total hydrogen

11.4 Total hydrogen mass fraction, less that present as moisture

11.5 Additional information

12 Precision

12.1 Repeatability limit

12.2 Reproducibility limit

13 Test report

Bibliography

BS ISO 625:2025

Coal and coke. Determination of carbon and hydrogen. Liebig method

Current

Published:

31 Aug 2025

1 Scope