ISO 13320-2020 PDF

Full title and description

ISO 13320:2020 — Particle size analysis — Laser diffraction methods. This International Standard specifies principles, instrument qualification, measurement procedures and reporting requirements for the determination of particle size distributions by laser diffraction (light‑scattering) techniques for many two‑phase systems (powders, sprays, aerosols, suspensions, emulsions and gas bubbles in liquids). The technique uses an optical model that assumes spherical particles; for non‑spherical particles results are reported as an equivalent spherical size distribution.

Abstract

This document provides guidance on instrument qualification and particle size distribution measurement through analysis of light‑scattering properties. It applies (under normal conditions) to particle sizes from approximately 0.1 µm to 3 mm, with the possibility of extension beyond those limits with special instrumentation and conditions. The standard covers instrument set‑up, sample presentation (wet/dry), selection of an optical model, data inversion to produce size distributions, verification/calibration and reporting including uncertainty considerations.

General information

• Status: Published (International Standard; confirmed in systematic review 2025).
• Publication date: 6 January 2020 (Edition 2, published January 2020).
• Publisher: ISO — International Organization for Standardization.
• ICS / categories: 19.120 (Particle size analysis / sieving).
• Edition / version: 2 (second edition, 2020).
• Number of pages: 59 pages (ISO published text).

Scope

ISO 13320:2020 is applicable to the measurement of particle size distributions by laser diffraction for a broad range of sample types and sample‑presentation modes (dry dispersion, wet dispersion, in‑line, at‑line and off‑line measurements). It specifies requirements for instrument location and environmental control, sample inspection and preparation, dispersion and concentration control, selection of an appropriate optical model, data collection and inversion, verification/calibration and result reporting. The standard is intended for particle sizes normally ranging from about 0.1 µm to 3 mm, with extensions possible for special equipment and conditions.

Key topics and requirements

• Principle and theory of laser diffraction and typical optical arrangements (detectors, scattering angles).
• Instrument installation, environmental and vibration control requirements.
• Sample inspection, representative sampling, sample preparation, dispersion (wet and dry) and concentration control.
• Instrument qualification, calibration/verification procedures and use of reference materials.
• Selection of an appropriate optical model (assumptions about refractive index, absorption and spherical equivalence) and inversion algorithms to obtain particle size distributions.
• Requirements for data collection, robustness checks, resolution and sensitivity assessment.
• Reporting conventions for size distributions, units, graphical and tabular presentation and estimation of measurement uncertainty.
• Guidance on limitations of the technique (effects for non‑spherical particles, multiple scattering, refractive index mismatches and range limits).

Typical use and users

Used by testing and calibration laboratories, instrument manufacturers, R&D groups and quality control teams across pharmaceuticals, chemicals, food, minerals, cosmetics, environmental monitoring and process industries. Typical tasks include instrument commissioning and verification, routine QC of powders and suspensions, method development, inter‑laboratory comparisons and reporting of batch or product particle size distributions.

Related standards

ISO 13320:2020 is part of a family of particle‑analysis standards. It replaced ISO 13320:2009. Related standards and documents commonly referenced together include the ISO 9276 series (representation and reporting of particle size and shape results), ISO 13319 (electrical sensing zone methods), ISO 13322‑1 (image analysis methods — static image analysis), ISO 22412 (dynamic light scattering) and other technique‑specific standards such as ISO 19430 (particle tracking analysis). These related standards provide complementary methods, reporting formats and guidance for uncertainty and morphology description.

Keywords

particle size analysis; laser diffraction; light scattering; particle size distribution; PSD; instrument qualification; calibration; sample dispersion; wet dispersion; dry dispersion; optical model; measurement uncertainty; ISO 13320.

FAQ

Q: What is this standard?

A: ISO 13320:2020 is the international standard that specifies principles, procedures and reporting requirements for particle size analysis using laser diffraction (light‑scattering) methods.

Q: What does it cover?

A: It covers instrument set‑up and location, sample inspection and preparation, dispersion and concentration control, selection of optical models and inversion methods, verification and calibration, data collection and reporting (including uncertainty). It applies to many two‑phase systems (powders, sprays, suspensions, emulsions, aerosols) and to particle sizes typically from ~0.1 µm to 3 mm (with possible extension using special arrangements).

Q: Who typically uses it?

A: Testing and calibration laboratories, instrument manufacturers, R&D and quality control personnel in pharmaceuticals, chemicals, food, minerals, cosmetics, environmental monitoring and process industries. They use it for method development, routine QC, instrument qualification and inter‑laboratory comparison.

Q: Is it current or superseded?

A: Current — ISO 13320:2020 is the second edition (published 6 January 2020) and was confirmed in the 2025 systematic review; it replaced ISO 13320:2009.

Q: Is it part of a series?

A: It belongs to the broader set of ISO particle analysis standards (for example, the ISO 9276 series for representation of results, ISO 13319 for ESZ methods, ISO 13322 for image analysis methods and other technique‑specific standards). These complementary documents address alternative measurement techniques, reporting formats and uncertainty considerations.

Q: What are the key keywords?

A: Particle size analysis; laser diffraction; light scattering; PSD; instrument qualification; calibration; dispersion; wet/dry measurement; optical model; measurement uncertainty.