ISO Guide 33-2015 PDF

Full title and description

ISO Guide 33:2015 — Reference materials — Good practice in using reference materials. The Guide provides practical guidance on the use of reference materials (RMs) and certified reference materials (CRMs) in measurement processes, including applications such as quality control, calibration, assessment of precision and trueness, and the establishment of conventional scales.

Abstract

ISO Guide 33:2015 describes good practice in selecting and using reference materials and certified reference materials (CRMs) in laboratory and measurement contexts. It explains the differing characteristics and intended uses of RMs and CRMs, addresses metrological traceability for CRM property values, and gives guidance on handling, certificate interpretation, and appropriate applications (for example precision control, bias assessment and calibration). The Guide limits its treatment of RM production to fundamentals of small‑scale preparation and value assignment used by laboratories; larger‑scale production and full producer requirements are covered in other Guides (e.g., Guides 34 and 35).

General information

• Status: Withdrawn — replaced by ISO 33403:2024.
• Publication date: 5 February 2015 (publication stage recorded as 2015-02-05).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 71.040.30 (Chemical reagents).
• Edition / version: Edition 3 (2015).
• Number of pages: 31 pages.

Scope

The Guide covers good practice in using RMs and CRMs in measurement processes — including assessing precision and trueness of measurement methods, quality control, assigning values to materials, calibration, and establishing conventional scales. It clarifies which types of RM are suitable for which purposes, and gives instructions on handling and certificate interpretation; it does not replace the more detailed requirements for large‑scale RM production and producer competence (addressed in Guides/standards such as ISO Guides 34/35 and ISO 17034).

Key topics and requirements

• Definitions and classification of reference materials and certified reference materials.
• Guidance on appropriate uses of RMs/CRMs (precision control, bias assessment, calibration, value assignment, maintaining conventional scales).
• Explanation of metrological traceability for CRM property values and limitations for non‑CRM RMs.
• Instructions on interpreting certificates, reading traceability statements, and handling RMs correctly.
• Clarification of the Guide’s limits (small‑scale preparation fundamentals only; larger scale production and producer competence are covered elsewhere).

Typical use and users

Intended users include laboratory personnel, quality managers, accreditation bodies, metrologists, RM purchasers and users, and organizations involved in method validation and calibration. The Guide is used as practical guidance for selecting, applying and interpreting the use of RMs/CRMs in routine and research measurement activities.

Related standards

Relevant related documents include ISO 33403:2024 (which supersedes/replaces ISO Guide 33:2015), ISO Guides 34 and 35 (detailed producer requirements and value assignment), earlier versions of ISO Guide 33, and standards on RM producer competence such as ISO 17034. These documents together form the normative framework for production, certification and use of reference materials.

Keywords

reference material, certified reference material, CRM, RM, traceability, calibration, precision, trueness, quality control, reference material certificate, ISO Guide 33.

FAQ

Q: What is this standard?

A: ISO Guide 33:2015 is an ISO Guide titled "Reference materials — Good practice in using reference materials" that provides practical guidance on the use of RMs and CRMs in measurement processes.

Q: What does it cover?

A: It covers appropriate uses of RMs/CRMs (precision and trueness assessment, quality control, calibration, value assignment, conventional scales), certificate interpretation, handling, and the relationship between types of RMs and their intended applications; it limits treatment of RM production to small‑scale fundamentals.

Q: Who typically uses it?

A: Laboratory staff, quality and calibration managers, accreditation bodies, RM users and purchasers, metrologists and others involved in measurement assurance and method validation.

Q: Is it current or superseded?

A: ISO Guide 33:2015 has been withdrawn; it was officially withdrawn on 3 June 2024 and superseded by ISO 33403:2024. Users should consult ISO 33403:2024 for the current international standard on the requirements and recommendations for use of reference materials.

Q: Is it part of a series?

A: Yes — it sits within ISO guidance and standards related to reference materials and metrology. It complements and refers to other Guides/standards such as ISO Guides 34 and 35 and ISO 17034 (competence of RM producers).

Q: What are the key keywords?

A: Reference material, certified reference material (CRM), traceability, calibration, precision, trueness, RM certificate, handling, value assignment.