IEC GUIDE 115:2021

IEC GUIDE 115 ®
Edition 2.0 2021-03
REDLINE VERSION
GUIDE
colour
inside
Application of uncertainty of measurement to conformity assessment activities
in the electrotechnical sector

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IEC GUIDE 115 ®
Edition 2.0 2021-03
REDLINE VERSION
GUIDE
colour
inside
Application of uncertainty of measurement to conformity assessment activities
in the electrotechnical sector

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 17.020; 19.080 ISBN 978-2-8322-9569-4

– 2 – IEC GUIDE 115:2021 RLV  IEC 2021

CONTENTS
FOREWORD . 3

INTRODUCTION . 5

1 Scope . 7

2 Normative references . 7

3 Terms and definitions . 7

4 Application of uncertainty of measurement principles . 8

4.1 General . 8
4.2 Uncertainty of measurement principles . 10
4.3 Background. 10
4.4 Uncertainty of measurement principles – Application of procedures . 11
4.5 Conclusion . 13
5 Guidance on making uncertainty of measurement calculations including examples
of how to perform the calculations . 13
5.1 General principles . 13
5.2 Summary of steps when estimating uncertainty . 14
5.3 Simple example – Estimation of measurement uncertainty for a temperature-
rise test with thermocouples . 17
Annex A (informative) Uncertainty of measurement calculations for product conformity
assessment testing – Examples 1 to 6 . 19
Bibliography . 30

Figure 1 – Procedure 1: uncertainty of measurement calculated . 11
Figure 2 – Procedure 2: accuracy method . 12

Table 1 . 12
Table 2 . 13
Table 3 . 14
Table 4 . 17
Table 5 . 18
Table 6 . 18
Table A.1 – Input test. 20

Table A.2 – Input power test . 22
Table A.3 – Leakage current measurement test . 23
Table A.4 – Distance measurement using calliper gauge . 25
Table A.5 – Torque measurement . 27
Table A.6 – Pre-conditioning for ball pressure test . 28

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
APPLICATION OF UNCERTAINTY OF MEASUREMENT

TO CONFORMITY ASSESSMENT ACTIVITIES

IN THE ELECTROTECHNICAL SECTOR

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
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agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
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This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition GUIDE 115:2007. A vertical bar appears in the margin
wherever a change has been made. Additions are in green text, deletions are in
strikethrough red text.
– 4 – IEC GUIDE 115:2021 RLV  IEC 2021

This second edition of IEC Guide 115 has been prepared, in accordance with
ISO/IEC Directives, Part 1, Annex A, by IECEE/CTL. This is a non-mandatory guide in

accordance with SMB Decision 136/8.

This second edition cancels and replaces the first edition published in 2007.

The main changes with respect to the previous edition are as follows:

a) editorial alignment to ISO/IEC 17025:2017 without adapting the technical content;

b) references to ISO/IEC 17025:2005 and ISO/IEC 17025:2017 in order to help for the
transition to the new edition of ISO/IEC 17025.

The text of this IEC Guide is based on the following documents:
Four months' vote Report on voting
SMBNC/8/DV SMBNC/14/RV
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this Guide is English.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2, and
developed in accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC
Supplement, available at www.iec.ch/members_experts/refdocs. The main document types
developed by IEC are described in greater detail at www.iec.ch/standardsdev/publications.

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INTRODUCTION
This document has been prepared by the IECEE Committee of Testing Laboratories (CTL) to

provide guidance on the practical application of the measurement uncertainty requirements of

ISO/IEC 17025 to the electrical safety testing conducted within the IECEE CB Scheme.

The IECEE CB Scheme is a multilateral, international agreement, among over 40 countries

and some 60 national certification bodies, for the acceptance of test reports on electrical

products tested to IEC standards.

The aim of the CTL is, among other tasks, to define a common understanding of the test

methodology with regard to the IEC standards as well as to ensure and continually improve
the repeatability and reproducibility of test results among the member laboratories.
The practical approach to measurement uncertainty outlined in this document has been
adopted for use in the IECEE Schemes, and is also extensively used around the world by
testing laboratories engaged in testing electrical products to national safety standards.
This document is of particular interest to the following IEC technical committees, which may
can decide to make use of it if necessary:

TECHNICAL COMMITTEE 13: EQUIPMENT FOR ELECTRICAL ENERGY MEASUREMENT,
TARIFF AND LOAD CONTROL
ELECTRICAL ENERGY MEASUREMENT AND CONTROL
TECHNICAL COMMITTEE 17: HIGH-VOLTAGE SWITCHGEAR AND CONTROLGEAR
TECHNICAL COMMITTEE 18: ELECTRICAL INSTALLATIONS OF SHIPS AND OF MOBILE
AND FIXED OFFSHORE UNITS
TECHNICAL COMMITTEE 20: ELECTRIC CABLES
TECHNICAL COMMITTEE 21: SECONDARY CELLS AND BATTERIES
TECHNICAL COMMITTEE 22: POWER ELECTRONIC SYSTEMS AND EQUIPMENT
TECHNICAL COMMITTEE 23: ELECTRICAL ACCESSORIES
TECHNICAL COMMITTEE 32: FUSES
TECHNICAL COMMITTEE 33: POWER CAPACITORS AND THEIR APPLICATIONS
TECHNICAL COMMITTEE 34: LAMPS AND RELATED EQUIPMENT LIGHTING
TECHNICAL COMMITTEE 35: PRIMARY CELLS AND BATTERIES
TECHNICAL COMMITTEE 38: INS
...