EN 62788-1-4:2016

SLOVENSKI STANDARD
01-februar-2017
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Measurement procedures for materials used in photovoltaic modules - Part 1-4:
Encapsulants - Measurement of optical transmittance and calculation of the solar-
weighted photon transmittance, yellowness index, and UV cut-off frequency
Ta slovenski standard je istoveten z: EN 62788-1-4:2016
ICS:
17.180.99 'UXJLVWDQGDUGLY]YH]L] Other standards related to
RSWLNRLQRSWLþQLPLPHUMHQML optics and optical
measurements
27.160 6RQþQDHQHUJLMD Solar energy engineering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 62788-1-4

NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2016
ICS 27.160
English Version
Measurement procedures for materials used in photovoltaic
modules - Part 1-4: Encapsulants - Measurement of optical
transmittance and calculation of the solar-weighted photon
transmittance, yellowness index, and UV cut-off wavelength
(IEC 62788-1-4:2016)
Procédures de mesure des matériaux utilisés dans les Messverfahren für Werkstoffe, die in Photovoltaikmodulen
modules photovoltaïques - Partie 1-4: Encapsulants - verwendet werden - Teil 1-4: Verkapselungsstoffe -
Mesurage du facteur de transmission optique et calcul du Messung der optischen Transmission und Berechnung der
facteur de transmission photonique à pondération solaire, solargewichteten Photonentransmission, des
de l'indice de jaunissement et de la fréquence de coupure Vergilbungsindex und der UV-Grenzfrequenz
des UV (IEC 62788-1-4:2016)
(IEC 62788-1-4:2016)
This European Standard was approved by CENELEC on 2016-11-01. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 62788-1-4:2016 E
European foreword
The text of document 82/1148/FDIS, future edition 1 of IEC 62788-1-4, prepared by IEC/TC 82 "Solar
photovoltaic energy systems" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN 62788-1-4:2016.
The following dates are fixed:
(dop) 2017-08-01
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2019-11-01
standards conflicting with the
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 62788-1-4:2016 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated :

IEC/TS 61836 NOTE Harmonized as CLC/TS 61836.
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.

NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu
Publication Year Title EN/HD Year

IEC 60904-3 -  Photovoltaic devices - EN 60904-3 -
Part 3: Measurement principles for
terrestrial photovoltaic (PV) solar devices
with reference spectral irradiance data
ISO 291 2008 Plastics - Standard atmospheres for EN ISO 291 2008
conditioning and testing
ISO 11664-1 2007 Colorimetry - EN ISO 11664-1 2011
Part 1: CIE standard colorimetric observers
ISO 11664-2 2007 Colorimetry - EN ISO 11664-2 2011
Part 2: CIE standard illuminants
ISO 13468-2 1999 Plastics - Determination of the total EN ISO 13468-2 2006
luminous transmittance of transparent
materials - Part 2: Double-beam instrument
ISO 17223 2014 Plastics - Determination of yellowness - -
index and change in yellowness index
1)
ASTM E424-71 2007 Standard test methods for solar energy - -
transmittance and reflectance (Terrestrial)
of sheet materials
1)
Superseded by ASTM E424-71:2015.
IEC 62788-1-4 ®
Edition 1.0 2016-09
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Measurement procedures for materials used in photovoltaic modules –

Part 1-4: Encapsulants – Measurement of optical transmittance and calculation

of the solar-weighted photon transmittance, yellowness index, and UV cut-off

wavelength
Procédures de mesure des matériaux utilisés dans les modules

photovoltaïques –
Partie 1-4: Encapsulants – Mesurage du facteur de transmission optique

et calcul du facteur de transmission photonique à pondération solaire,

de l'indice de jaunissement et de la fréquence de coupure des UV

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 27.160 ISBN 978-2-8322-3634-5

– 2 – IEC 62788-1-4:2016  IEC 2016
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references. 5
3 Terms and definitions . 6
4 Principle . 7
5 Apparatus . 7
6 Test specimens . 7
6.1 Nominal (and unweathered) transmittance to the cell . 7
6.2 Weathering studies . 8
6.3 Glass for superstrates/substrates . 9
6.4 Number of specimens . 9
6.5 Preconditioning of specimens . 9
7 Measurement procedure . 9
7.1 General . 9
7.2 Specimen preparation . 9
7.3 Instrument calibration (baseline measurements) . 9
7.4 Specimen measurements . 10
7.5 Witness measurements . 10
8 Calculation and expression of results . 10
8.1 Post-processing of data . 10
8.2 Calculation of weighted transmittance . 10
8.3 Calculation of the Yellowness Index (YI) . 11
8.4 Calculation of the UV cut-off wavelength . 11
9 Uncertainty of measurements . 11
10 Test report. 12
Annex A (informative) Advanced analysis of transmittance (absorption coefficients) . 14
Annex B (informative) Applying the quantum efficiency of a specific cell technology . 16
Bibliography . 18

Table 1 – Details of the solar weight transmittance parameters . 11

IEC 62788-1-4:2016  IEC 2016 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MEASUREMENT PROCEDURES FOR MATERIALS
USED IN PHOTOVOLTAIC MODULES –

Part 1-4: Encapsulants – Measurement of optical transmittance and
calculation of the solar-weighted photon transmittance,
yellowness index, and UV cut-off wavelength

FOREWORD
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