>>
<<
ISO 33403:2024(en)
ISO - Cover page
Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Conventions
6 RMs and their role in measurement
 6.1 Common applications of RMs
 6.2 Property values
  6.2.1 General
  6.2.2 Specification of the property
 6.3 Uncertainty statement
 6.4 Traceability statement
7 Handling of RMs and CRMs
8 Assessment of precision
 8.1 General
 8.2 Number of replicate measurements
 8.3 Requirements with respect to the RM
 8.4 Measurement
 8.5 Data treatment
 8.6 Calculation and assessment of precision
9 Bias assessment
 9.1 General
 9.2 Approach to bias checking
 9.3 Utilizing bias data
10 Calibration
 10.1 General
 10.2 Practical considerations for calibration
 10.3 Calibration models
11 Assigning values to other materials
 11.1 General
 11.2 Pure substances
 11.3 Preparation of calibrants
12 Conventional scales
13 Selection of RMs and CRMs
 13.1 General
 13.2 Selection of a CRM
 13.3 Selection of RMs
 13.4 Relevance to the measurement system
Annex A (informative) Calibration models and associated uncertainty models
Annex B (informative) Decision errors
Annex C (informative) Example of conventional scales
Bibliography
30mm
20mm
15mm
15mm
10mm
17mm

International

Standard

ISO 33403
Reference materials — Requirements and recommendations for use
Matériaux de référence — Exigences et recommandations pour l'utilisation
Reference number
ISO 33403:2024(en)
First edition
2024-06
30mm
20mm
15mm
15mm
10mm
17mm
30mm
20mm
15mm
15mm
10mm
17mm

ContentsPage

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 documents 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 334, Reference materials.
This first edition cancels and replaces ISO Guide 33:2015, which has been technically revised.
The main changes are as follows:
title modified;
1.5 removed;
5.3 and 5.4 removed;
Figure 1 revised and explanation inserted;
6.1.4: former Annex A Table A.1 inserted as Table 1;
9.1.3 removed;
9.2.1 revised;
9.3.1 and 9.3.2 revised and merged into 9.3.1
10.2.1 moved to 10.1.1 and former 10.1.1. added as 10.1.2;
12.2 and 12.3 moved into the new Annex C;
former Annex B now Annex A;
former Annex C now Annex B;
Bibliography revised.
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.

Introduction

This document provides general recommendations on the use of reference materials (RMs). These recommendations are exemplified by real-world examples, which to some degree also reflect the level of complexity associated with RMs. This level of detail is deemed to be useful for users of RMs and anyone who has a responsibility in the quality management in laboratories, e.g. drafters, reviewers, managers and assessors of procedures, working instructions and standard operating procedures.
For certified reference materials (CRMs), the metrological traceability of the property values to international scales or other measurement standards has been established. For RMs that are not CRMs, this kind of traceability of property values has often not been established. Nevertheless, these RMs can still be used for assessing parts of measurement procedures, including evaluating various levels of precision.
Mainstream applications of RMs are listed in 6.1.1. Not all types of RMs can be used for all indicated purposes.
30mm
20mm
15mm
15mm
10mm
17mm

International StandardISO 33403:2024(en)
Reference materials — Requirements and recommendations for use

1Scope

This document describes good practice in using reference materials (RMs), and certified reference materials (CRMs) in particular, in measurement processes. These uses include:
— the assessment of precision and trueness of measurement methods;
— quality control;
— assigning values to materials;
— calibration;
— establishing conventional scales.
This document also relates key characteristics of various types of RMs to the different applications.
The preparation of RMs for calibration is also part of the scope of ISO 17034 and ISO 33405. The treatment in this document is limited to the fundamentals of small-scale preparation of RMs and the value assignment, as used by laboratories to calibrate their equipment. Larger scale production of such RMs, with the possible aim of distribution, is beyond the scope of this document. This type of activity is covered in ISO 17034 and ISO 33405.

2Normative references

The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO Guide 30, Reference materials — Selected terms and definitions
ISO/IEC Guide 99, International vocabulary of metrology — Basic and general concepts and associated terms (VIM)

3Terms and definitions

For the purposes of this document, the terms and definitions given in ISO Guide 30 and ISO/IEC Guide 99 apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
ISO Online browsing platform: available at https://www.iso.org/obp
IEC Electropedia: available at https://www.electropedia.org/
30mm
20mm
15mm
15mm
10mm
17mm

Bibliography
[1]
ISO 3534-1, Statistics — Vocabulary and symbols — Part 1: General statistical terms and terms used in probability
[2]
ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results — Part 1: General principles and definitions
[3]
ISO 5725-2, Accuracy (trueness and precision) of measurement methods and results — Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method
[4]
ISO 5725-3, Accuracy (trueness and precision) of measurement methods and results — Part 3: Intermediate precision and alternative designs for collaborative studies
[5]
ISO 5725-4, Accuracy (trueness and precision) of measurement methods and results — Part 4: Basic methods for the determination of the trueness of a standard measurement method
[6]
ISO 5725-5, Accuracy (trueness and precision) of measurement methods and results — Part 5: Alternative methods for the determination of the precision of a standard measurement method
[7]
ISO 5725-6, Accuracy (trueness and precision) of measurement methods and results — Part 6: Use in practice of accuracy values
[8]
ISO 6143, Gas analysis — Comparison methods for determining and checking the composition of calibration gas mixtures
[9]
ISO 7870-5, Control charts — Part 5: Specialized control charts
[10]
ISO 15189, Medical laboratories — Requirements for quality and competence
[11]
ISO 15194, In vitro diagnostic medical devices — Measurement of quantities in samples of biological origin — Requirements for certified reference materials and the content of supporting documentation
[12]
ISO 16269-4, Statistical interpretation of data — Part 4: Detection and treatment of outliers
[13]
ISO 17034, General requirements for the competence of reference material producers
[14]
ISO 33406, Guidance for the production of reference materials with qualitative properties
[15]
ISO 33401, Reference materials — Contents of certificates, labels and accompanying documentation
[16]
ISO 33405, Reference materials — Approaches for characterization and assessment of homogeneity and stability
[17]
ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in measurement (GUM:1995)
[18]
ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories
[19]
NEN 7779:2008, Environment, food and feed - Measurement uncertainty
[20]
ELLISON S.L.R. ROSSLEIN M., WILLIAMS A., eds. Eurachem/Citac Guide — Quantifying uncertainty in analytical measurement. LGC, London, Third Edition, 2012
[21]
King B. ed. Eurachem (2002), The selection and use of reference materials - a basic guide for laboratories and accreditation bodies, URL: https://www.eurachem.org
[22]
SNEDECOR G.W., COCHRAN, W.G. Statistical Methods (8th edition). Ames, Iowa. Blackwell Publishing Professional
[23]
VESPER H.W., MILLER, W.G., MYERS, G.L. Reference Materials and Commutability. Clin. Biochem. Rev. 2007, 28(4), pp. 139-147
30mm
20mm
15mm
15mm
10mm
17mm
ICS 71.040.30
Price based on 26 pages
iso.org