National foreword

This British Standard is the UK implementation of ISO 501:2025. It supersedes BS ISO 501:2012, which is withdrawn.

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 30 June 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).

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This document was prepared by Technical Committee ISO/TC 27, Coal and coke, Subcommittee SC 5, Methods of analysis.

This fifth edition cancels and replaces the fourth edition (ISO 501:2012), which has been technically revised.

The main changes are as follows:

replaced the word "should" with "shall" throughout the document;
corrected dimension expressions e.g. 26 ± 1,0 mm to 26 mm ± 1 mm;
standardised the reporting of ½ as 0,5.

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.

1 Scope

This document specifies a method for determining the swelling properties of hard coal when heated in a covered crucible.

NOTE The "crucible swelling number" (CSN) is also known as the "free swelling index" (FSI).

2 Normative references

3 Terms and definitions

4 Principle

5 Preparation of the test sample

6 Apparatus

6.1

6.2

6.3

6.4

6.5

6.6

6.7

6.8

6.9

7 Preparation of apparatus

8 Procedure

9 Expression of results

10 Precision of the method

10.1 Repeatability

10.2 Reproducibility

11 Test report

BS ISO 501:2025

Hard coal. Determination of the crucible swelling number

Current

Published:

30 Jun 2025