Overview
ISO/TS 4807:2022 - "Reference materials for particle size measurement - Specification of requirements" provides user-focused guidance to help select and use reference materials (RMs) for particle size analysis. The technical specification describes the fundamental requirements that particle-form RMs (certified or non‑certified) must meet to be fit for purpose. It is limited to particulate RMs and does not cover other RM forms (e.g., calibration grids) or sample preparation beyond the sample as received by the user.
Key topics and requirements
- Measurand definitions: Clarifies how particle size measurands should be specified, including operationally defined measurands and the need to document measurement procedures (e.g., equivalent diameters and conditions under which they represent actual particle size).
- Metrological traceability: Describes the expectation that measurement results can be linked to references through a documented chain of calibrations, with associated uncertainties.
- Types of RMs: Differentiates certified vs non‑certified RMs, primary/secondary/tertiary CRMs, and material morphology (spherical/non‑spherical, monomodal/monodisperse). (Example definition: a monodisperse material is characterized in the document by a specific percentile ratio criterion.)
- Material properties: Addresses porous vs dense particles, homogeneity and stability requirements relevant to particle size RMs.
- Practical handling: Provides guidance on storage, handling and use to preserve RM integrity.
- Use‑case requirements: Specifies RM attributes for:
- Instrument verification / design qualification
- Installation qualification
- Calibration (including certified value traceability and uncertainty)
- Operational qualification / proficiency testing
- Statistical quality control and performance qualification
- Documentation expectations: For CRMs, certificates must state the assigned value, uncertainty and metrological traceability.
Applications and intended users
ISO/TS 4807 is practical for:
- Analytical laboratories performing particle size characterization (laser diffraction, dynamic light scattering, sieving, image analysis)
- RM producers and certification bodies developing particle RMs or CRMs
- Instrument manufacturers specifying verification and calibration materials
- Quality assurance / regulatory teams seeking traceable measurement systems
- Proficiency testing organizers and method developers setting acceptance criteria
This specification helps users choose RMs that support calibration, method validation, instrument qualification and ongoing quality control for reliable particle size measurement.
Related standards
- ISO Guide 30 and ISO/IEC Guide 99 (terminology and metrological concepts)
- ISO/TS 14411-1 (referenced for monodisperse material criteria)
- ISO 17034 (reference material producers / CRMs)
Keywords: ISO/TS 4807:2022, reference materials, particle size measurement, RMs, CRMs, metrological traceability, particle characterization, calibration, instrument verification.