National foreword

This British Standard is the UK implementation of ISO 22412:2017. It supersedes BS 3406‑8:1997 and BS ISO 22412:2008 which are withdrawn.

The UK participation in its preparation was entrusted to Technical Committee LBI/37, Particle characterization including sieving.

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

This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.

© The British Standards Institution 2017.

Published by BSI Standards Limited 2017

ISBN 978 0 580 88273 9

ICS 19.120

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 28 February 2017.

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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 22412 was prepared by Technical Committee ISO/TC 24 Subcommittee SC 4, Particle characterization. This second revision combines and replaces ISO 13321 (photon correlation spectroscopy) and the first edition of ISO 22412.

Introduction

Particle sizing in the submicrometre size range is nowadays performed on a routine basis using the dynamic light scattering (DLS) method, which probes the hydrodynamic mobility of the particles The success of the technique is mainly based on the fact that it provides estimates of the average particle size and size distribution within a few minutes, and that user-friendly commercial instruments are available. Nevertheless, proper use of the instrument and interpretation of the result require certain precautions.

ISO 13321, photon correlation spectroscopy, was developed in 1996. A general standard for DLS (ISO 22412) was developed in 2008 . The current edition of ISO 22412 is a combination of ISO 13321 and the first edition of ISO 22412.

Several methods have been developed for DLS. These methods can be classified in several ways:

by the difference in raw data acquisition (autocorrelation, cross-correlation, and frequency analysis)
by the difference in optical set-up (self-beating/homodyne vs. heterodyne mode)
by the angle of observation.

In addition, instruments show differences with respect to the type of laser source and often allow application of different data analysis algorithms (e. g., cumulants, NNLS, CONTIN, etc.).

1 Scope

This International Standard specifies the application of dynamic light scattering (DLS) to the measurement of average hydrodynamic particle size and the measurement of the size distribution of mainly submicrometre-sized particles, emulsions or fine bubbles dispersed in liquids. DLS is also referred to as quasi-elastic light scattering (QELS) and photon correlation spectroscopy (PCS), although it actually is one of the measurement techniques.

This International Standard is applicable to the measurement of a broad range of dilute and concentrated suspensions. The principle of dynamic light scattering for a concentrated suspension is the same as for a dilute suspension. However, specific requirements for the instrument set-up and specification of test sample preparation are required for concentrated suspensions. At high concentrations, particle-particle interactions and multiple light scattering can become dominant and may result in apparent particle sizes that differ between concentrated and dilute suspensions.

2 Normative references

3 Terms and definitions

4 Symbols, abbreviated terms and units

5 Principle

6 Apparatus

6.1

6.2

6.3

6.4

6.5

6.6

6.7

7 Test sample preparation

7.1 General

7.2 Concentration limits

7.3 Checks for concentration suitability

8 Measurement procedure

9 Evaluation of results

9.1 General

9.2 Correlation analysis

9.3 Frequency analysis

10 System qualification and quality control

10.1 System qualification

10.2 Quality control of measurement results

10.3 Method precision and measurement uncertainty

11 Test report

Bibliography

BS ISO 22412:2017

Particle size analysis. Dynamic light scattering (DLS)

Published:

28 Feb 2017

Withdrawn:

9 Sep 2025