IEC 60904-4:2019

IEC 60904-4 ®
Edition 2.0 2019-11
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Photovoltaic devices –
Part 4: Reference solar Photovoltaic reference devices – Procedures
for establishing calibration traceability

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form
or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from
either IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC
copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or
your local IEC member National Committee for further information.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform Electropedia - www.electropedia.org
The advanced search enables to find IEC publications by a The world's leading online dictionary on electrotechnology,
variety of criteria (reference number, text, technical containing more than 22 000 terminological entries in English
committee,…). It also gives information on projects, replaced and French, with equivalent terms in 16 additional languages.
and withdrawn publications. Also known as the International Electrotechnical Vocabulary

(IEV) online.
IEC Just Published - webstore.iec.ch/justpublished
Stay up to date on all new IEC publications. Just Published IEC Glossary - std.iec.ch/glossary
details all new publications released. Available online and 67 000 electrotechnical terminology entries in English and
once a month by email. French extracted from the Terms and Definitions clause of
IEC publications issued since 2002. Some entries have been
IEC Customer Service Centre - webstore.iec.ch/csc collected from earlier publications of IEC TC 37, 77, 86 and
If you wish to give us your feedback on this publication or CISPR.

need further assistance, please contact the Customer Service

Centre: sales@iec.ch.
IEC 60904-4 ®
Edition 2.0 2019-11
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Photovoltaic devices –
Part 4: Reference solar Photovoltaic reference devices – Procedures

for establishing calibration traceability

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.160 ISBN 978-2-8322-7608-2

– 2 – IEC 60904-4:2019 RLV © IEC 2019
CONTENTS
FOREWORD . 4
1 Scope and object . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Requirements for traceable calibration procedures of PV reference solar devices . 9
5 Uncertainty analysis . 10
6 Calibration report . 10
7 Marking . 11
Annex A (informative) Examples of validated calibration procedures . 12
A.1 General . 12
A.1.1 Overview . 12
A.1.2 Examples of validated methods . 12
A.1.3 List of common symbols . 12
A.1.4 Common formulae . 13
A.1.5 Reference documents . 15
A.2 Global sunlight method (GSM) . 15
A.2.1 General . 15
A.2.2 Equipment . 16
A.2.3 Measurements . 16
A.2.4 Data analysis . 17
A.2.5 Uncertainty estimates . 19
A.2.6 Reference documents . 19
A.3 Differential spectral responsivity calibration (DSR calibration) . 20
A.3.1 General . 20
A.3.2 Equipment . 20
A.3.3 Test procedure . 21
A.3.4 Data analysis . 22
A.3.5 Uncertainty estimate . 24
A.3.6 Reference documents . 27
A.4 Solar simulator method(SSM) . 28
A.4.1 General . 28
A.4.2 Equipment . 28
A.4.3 Calibration procedure . 28
A.4.4 Data analysis . 29
A.4.5 Uncertainty estimate . 29
A.4.6 Reference documents . 30
A.5 Direct sunlight method (DSM) . 30
A.5.1 General . 30
A.5.2 Equipment . 31
A.5.3 Measurements . 31
A.5.4 Data analysis . 31
A.5.5 Uncertainty estimate . 32
A.5.6 Reference documents . 32
Bibliography . 34

Figure 1 – Schematic of most common reference instruments and transfer methods
used in the traceability chains for solar irradiance detectors . 9
Figure A.1 – Block diagram of differential spectral responsivity calibration
superimposing chopped monochromatic radiation DE(l) and DC bias radiation E . 25
b
Figure A.2 – Optical arrangement of differential spectral responsivity calibration . 27
Figure A.3 – Schematic apparatus of the solar simulator method . 30

Table 1 – Examples of reference instruments used in a traceability chain of time and
solar irradiance . 9
Table A.1 – Typical uncertainty components (k = 2) of global sunlight method . 19
Table A.2 – Typical Uncertainty components (k = 2) of differential spectral responsivity
calibration method on PV reference devices . 24
Table A.3 – Example of uncertainty components (k = 2) of a solar simulator method
calibration . 29
Table A.4 – Typical uncertainty components (k = 2) of a solar simulator method

calibration when WRR traceable cavity radiometer is used. 29
Table A.5 – Typical uncertainty components (k = 2) of a direct sunlight method using
temperature dependent spectral correction factor (Formula (A.16)), without applying
a correction factor for the WRR to SI scale . 32

– 4 – IEC 60904-4:2019 RLV © IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PHOTOVOLTAIC DEVICES –
Part 4: Reference solar Photovoltaic reference devices –
Procedures for establishing calibration traceability

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,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This redline version of the official IEC Standard allows the user to identify the changes
made to the previous edition. A vertical bar appears in the margin wherever a change
has been made. Additions are in green text, deletions are in strikethrough red text.

International Standard IEC 60904-4 has been prepared by IEC technical committee 82: Solar
photovoltaic energy systems.
This second edition cancels and replaces the first edition published in 2009. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with r
...