IEC 60904-4:2009

IEC 60904-4 ®
Edition 1.0 2009-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Photovoltaic devices –
Part 4: Reference solar devices – Procedures for establishing calibration
traceability
Dispositifs photovoltaïques –
Partie 4: Dispositifs solaires de référence – Procédures pour établir la traçabilité
de l'étalonnage
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IEC 60904-4 ®
Edition 1.0 2009-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Photovoltaic devices –
Part 4: Reference solar devices – Procedures for establishing calibration
traceability
Dispositifs photovoltaïques –
Partie 4: Dispositifs solaires de référence – Procédures pour établir la traçabilité
de l'étalonnage
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
T
CODE PRIX
ICS 27.160 ISBN 978-2-88910-323-2
– 2 – 60904-4 © IEC:2009
CONTENTS
FOREWORD.3

1 Scope and object.5

2 Normative references .5

3 Terms and definitions .5

4 Requirements for traceable calibration procedures of PV reference solar devices .7

5 Uncertainty analysis .8

6 Calibration report.8

7 Marking .8
Annex A (informative) Examples of validated calibration procedures.10
Bibliography.24

Figure 1 – Schematic of most common reference instruments and transfer methods
used in the traceability chains for solar irradiance detectors. .7
Figure A.1 – Block diagram of differential spectral responsivity calibration
superimposing chopped monochromatic radiation DE(l) and DC bias radiation E .18
b
Figure A.2 – Optical arrangement of differential spectral responsivity calibration. .19
Figure A.3 – Schematic apparatus of the solar simulator method. .21

Table 1 – Examples of reference instruments, used in a traceability chain of time and
solar irradiance.7
Table A.1 – Typical uncertainty components (k = 2) of global sunlight method .15
Table A.2 – Typical uncertainty components (k = 2) of a differential spectral
responsivity calibration .18
Table A.3 – Example of uncertainty components (k = 2) of a solar simulator method
calibration.21
Table A.4 – Typical uncertainty components (k = 2) of a solar simulator method
calibration when WRR traceable cavity radiometer is used .21
Table A.5 – Typical uncertainty components (k = 2) of a direct sunlight method .23

60904-4 © IEC:2009 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
PHOTOVOLTAIC DEVICES –
Part 4: Reference solar devices –

Procedures for establishing calibration traceability

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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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.
International Standard IEC 60904-4 has been prepared by IEC technical committee 82: Solar
photovoltaic energy systems.
The text of this standard is based on the following documents:
CDV Report on voting
82/533/CDV 82/561/RVC
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of IEC 60904 series, under the general title Photovoltaic devices, can be
found on the IEC website.
– 4 – 60904-4 © IEC:2009
The committee has decided that the contents of this publication will remain unchanged until

the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in

the data related to the specific publication. At this date, the publication will be

• reconfirmed,
• withdrawn,
• replaced by a revised edition, or

• amended.
60904-4 © IEC:2009 – 5 –
PHOTOVOLTAIC DEVICES –
Part 4: Reference solar devices –

Procedures for establishing calibration traceability

1 Scope and object
This part of IEC 60904 sets the requirements for calibration procedures intended to establish
the traceability of photovoltaic reference solar devices to SI units as required by IEC 60904-2.
This standard applies to photovoltaic (PV) reference solar devices that are used to measure
the irradiance of natural or simulated sunlight for the purpose of quantifying the performance
of PV devices. The use of a PV reference solar device is required in the application of
IEC 60904-1 and IEC 60904-3.
This standard has been written with single junction PV reference solar devices in mind, in
particular crystalline Silicon. However, the main part of the standard is sufficiently general to
include other technologies. The methods described in Annex A, however, are limited to single
junction technologies.
2 Normative references
The following referenced documents are indispensable for the application 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.
IEC 60904-2, Photovoltaic devices – Part 2: Requirements for reference solar devices
ISO/IEC 17025, General requirements for the competence of testing and calibration
laboratories
ISO 9059, Solar energy – Calibration of field pyrheliometers by comparison to a reference
pyrheliometer
ISO 9846, Solar energy – Calibration of a pyranometer using a pyrheliometer

ISO/IEC Guide 98-3: 2008, Uncertainty of measurement – Part 3: Guide to the expression of
uncertainty in measurement (GUM: 1995)
3 Terms and definitions
For the purposes of this document, the following ter
...