SIST EN IEC 62788-5-1:2020

SLOVENSKI STANDARD
SIST EN IEC 62788-5-1:2020
01-julij-2020
Merilni postopki za materiale, uporabljene v fotonapetostnih modulih - 5-1. del:
Robna tesnila - Priporočene preskusne metode za materiale robnih tesnil
Measurement procedures for materials used in photovoltaic modules - Part 5-1: Edge
seals - Suggested test methods for use with edge seal materials
Messverfahren für Werkstoffe, die in Photovoltaik-Modulen verwendet werden - Teil 5-1:
Kantenversiegelung - Empfohlene Prüfverfahren für die Verwendung mit
Kantenversiegelungsmaterialien
Procédures de mesure des matériaux utilisés dans les modules photovoltaïques - Partie
5-1: Joints d'étanchéité périphériques - Méthodes d’essai suggérées pour l’utilisation des
matériaux de joints d'étanchéité périphériques
Ta slovenski standard je istoveten z: EN IEC 62788-5-1:2020
ICS:
27.160 Sončna energija Solar energy engineering
83.140.50 Tesnila Seals
SIST EN IEC 62788-5-1:2020 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN IEC 62788-5-1:2020

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SIST EN IEC 62788-5-1:2020


EUROPEAN STANDARD EN IEC 62788-5-1

NORME EUROPÉENNE

EUROPÄISCHE NORM
May 2020
ICS 27.160

English Version
Measurement procedures for materials used in photovoltaic
modules - Part 5-1: Edge seals - Suggested test methods for use
with edge seal materials
(IEC 62788-5-1:2020)
Procédures de mesure des matériaux utilisés dans les Messverfahren für Werkstoffe, die in Photovoltaik-Modulen
modules photovoltaïques - Partie 5-1: Joints d'étanchéité verwendet werden - Teil 5-1: Kantenversiegelung -
périphériques - Méthodes d'essai suggérées pour Empfohlene Prüfverfahren für die Verwendung mit
l'utilisation des matériaux de joints d'étanchéité Kantenversiegelungsmaterialien
périphériques (IEC 62788-5-1:2020)
(IEC 62788-5-1:2020)
This European Standard was approved by CENELEC on 2020-04-23. 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, 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: Rue de la Science 23, B-1040 Brussels
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN IEC 62788-5-1:2020 E

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SIST EN IEC 62788-5-1:2020
EN IEC 62788-5-1:2020 (E)
European foreword
The text of document 82/1658/FDIS, future edition 1 of IEC 62788-5-1, prepared by IEC/TC 82 "Solar
photovoltaic energy systems" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 62788-5-1:2020.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2021-01-23
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2023-04-23
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 shall not be held responsible for identifying any or all such patent rights.

Endorsement notice
The text of the International Standard IEC 62788-5-1:2020 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 61215 (series) NOTE Harmonized as EN 61215 (series)
IEC 61730-1:2016 NOTE Harmonized as EN IEC 61730-1:2018 (not modified)


2

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SIST EN IEC 62788-5-1:2020
EN IEC 62788-5-1:2020 (E)
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
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.
NOTE 1  Where 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 60112 - Method for the determination of the proof - -
and the comparative tracking indices of solid
insulating materials
IEC 60216-5 - Electrical insulating materials - Thermal - -
endurance properties - Part 5: Determination
of relative temperature index (RTI) of an
insulating material
IEC 60243-1 2013 Electric strength of insulating materials - Test EN 60243-1 2013
methods - Part 1: Tests at power frequencies
IEC 60243-2 2013 Electric strength of insulating materials - Test EN 60243-2 2014
methods - Part 2: Additional requirements for
tests using direct voltage
IEC 60664-1 - Insulation coordination for equipment within - -
low-voltage supply systems - Part 1:
Principles, requirements and tests
IEC 60695-11-10 - Fire hazard testing - Part 11-10: Test flames EN 60695-11-10 -
- 50 W horizontal and vertical flame test
methods
IEC 61730-2 2016 Photovoltaic (PV) module safety qualification EN IEC 61730-2 2018
- Part 2: Requirements for testing
  +AC 2018-
06
IEC 62788-1-2 - Measurement procedures for materials used EN 62788-1-2 -
in photovoltaic modules - Part 1-2:
Encapsulants - Measurement of volume
resistivity of photovoltaic encapsulants and
other polymeric materials
3

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SIST EN IEC 62788-5-1:2020
EN IEC 62788-5-1:2020 (E)
IEC 62788-6-2 - Measurement procedures for materials used - -
in photovoltaic modules - Part 6-2: General
tests - Moisture permeation testing of
polymeric materials
ISO 62 - Plastics - Determination of water absorption EN ISO 62 -
ISO 1133-1 - Plastics - Determination of the melt mass- EN ISO 1133-1 -
flow rate (MFR) and melt volume-flow rate
(MVR) of thermoplastics - Part 1: Standard
method
ISO 4587 - Adhesives - Determination of tensile lap- - -
shear strength of rigid-to-rigid bonded
assemblies
ISO 6721-6 - Plastics - Determination of dynamic - -
mechanical properties - Part 6: Shear
vibration - Non-resonance method
ISO 11359-2 - Plastics - Thermomechanical analysis (TMA) - -
- Part 2: Determination of coefficient of linear
thermal expansion and glass transition
temperature
ISO 11443 - Plastics - Determination of the fluidity of - -
plastics using capillary and slit-die
rheometers
ISO 15512 - Plastics - Determination of water content EN ISO 15512 -
IEC/TS 61836 - Solar photovoltaic energy systems - Terms, - -
definitions and symbols
IEC/TS 62788-2 2017 Measurement procedures for materials used - -
in photovoltaic modules - Part 2: Polymeric
materials - Frontsheets and backsheets
UL 746B - Standard for Polymeric Materials - Long - -
Term Property Evaluations
UL 746C - Polymeric materials - Use in electrical - -
equipment evaluations
ASTM D3835-08 - Standard test methods determination of - -
properties of polymeric materials by means
of a capillary rheometer
ASTM D6869-03 - Standard test method for coulometric and - -
volumetric determination of moisture in
plastics using the Karl Fischer reaction (the
reaction of iodine with water)
ASTM D7191-10 - Standard test method for determination of - -
moisture in plastics by relative humidity
sensor

4

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SIST EN IEC 62788-5-1:2020




IEC 62788-5-1

®


Edition 1.0 2020-03




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE
colour

inside










Measurement procedures for materials used in photovoltaic modules –

Part 5-1: Edge seals – Suggested test methods for use with edge seal materials




Procédures de mesure des matériaux utilisés dans les modules

photovoltaïques –

Partie 5-1: Joints d’étanchéité périphériques – Méthodes d’essai suggérées


pour l’utilisation des matériaux de joints d'étanchéité périphériques













INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 27.160 ISBN 978-2-8322-7919-9




Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale

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SIST EN IEC 62788-5-1:2020
– 2 – IEC 62788-5-1:2020 © IEC 2020
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms,definitions and symbols . 6
3.1 Terms and definitions . 7
3.2 Symbols . 7
4 Recommended tests . 7
4.1 General . 7
4.2 Moisture permeation properties . 7
4.2.1 Moisture breakthrough time . 7
4.2.2 Fickian materials . 7
4.2.3 Non-Fickian materials . 8
4.3 Electrical properties . 8
4.3.1 Dielectric strength of the film . 8
4.3.2 Volume resistivity . 9
4.3.3 Comparative tracking index . 9
4.4 Adhesion testing . 9
4.4.1 General . 9
4.4.2 Lap shear strength . 9
4.4.3 “T” peel test . 10
4.4.4 90° peel test . 11
4.4.5 Butt joint test . 11
4.5 Durability of the materials . 12
4.5.1 Relative thermal endurance . 12
4.5.2 Dielectric strength degradation . 12
4.5.3 Accelerated stress testing . 13
4.6 Flame resistance . 15
4.7 Coefficient of thermal expansion . 15
4.8 Rheological properties . 15
4.8.1 Complex shear modulus . 15
4.8.2 Melt flow rate . 15
4.9 Other data . 15
5 Test report . 15
Bibliography . 17

Figure 1 – Lap shear test sample for proving cemented joint . 10
Figure 2 –Photograph (a)) and schematic (b)) of a z-tensile adhesion test specimen . 12
Figure 3 – Schematic of test structure for RTI or RTE dielectric durability testing . 13
Figure 4 – Test flow for cemented joint evaluation . 14

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SIST EN IEC 62788-5-1:2020
IEC 62788-5-1:2020 © IEC 2020 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

MEASUREMENT PROCEDURES FOR MATERIALS
USED IN PHOTOVOLTAIC MODULES –

Part 5-1: Edge seals –
Suggested test methods for use with edge seal materials

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.
International Standard IEC 62788-5-1 has been prepared by IEC technical committee 82: Solar
photovoltaic energy systems.
The text of this International Standard is based on the following documents:
FDIS Report on voting
82/1658/FDIS 82/1689/RVD

Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts in the IEC 62788 series, published under the general title Measurement
procedures for materials used in photovoltaic modules, can be found on the IEC website.

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SIST EN IEC 62788-5-1:2020
– 4 – IEC 62788-5-1:2020 © IEC 2020
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

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SIST EN IEC 62788-5-1:2020
IEC 62788-5-1:2020 © IEC 2020 – 5 –
MEASUREMENT PROCEDURES FOR MATERIALS
USED IN PHOTOVOLTAIC MODULES –

Part 5-1: Edge seals –
Suggested test methods for use with edge seal materials



1 Scope
This part of IEC 62788 provides procedures for standardized test methods for evaluating the
properties of materials designed to be used as edge seals. When modules are constructed with
impermeable (or extremely low permeability) front- and backsheets designed to protect
moisture-sensitive photovoltaic (PV) materials, there is still the possibility for moisture to get in
from the sides. This moisture ingress pathway can be restricted by using a low-diffusivity
material around the perimeter of a module between the impermeable front- and backsheets.
Alternatively, it can be desirable to use a low-diffusivity encapsulant, which may significantly
reduce moisture ingress over the lifetime of the module, and to evaluate it in a similar way to
an edge seal material.
In addition to restricting moisture ingress, edge seal materials also provide electrical insulation.
To perform these functions, edge seal materials are relied upon to adhere well.
The test methods described in this document are intended to be used to standardize the way
edge seals are evaluated. Only some of these tests are applied for IEC 61215 and IEC 61730,
and that status depends on the specific design. It is not required that all of these tests be
performed, but that if these measurements are made that they be performed as outlined here.
2 Normative 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.
IEC 60112, Method for the determination of the proof and the comparative tracking indices of
solid insulating materials
IEC 60243-1:2013, Electrical strength of insulating materials – Test methods – Part 1: Tests at
power frequencies
IEC 60243-2:2013, Electrical strength of insulating materials – Test methods – Part 2:
Additional requirements for tests using direct voltage
IEC 60216-5, Electrical insulating materials – Thermal endurance properties – Part 5:
Determination of relative thermal endurance index (RTE) of an insulating material
IEC 60664-1, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
IEC 60695-11-10, Fire hazard testing – Part 11-10: Test flames – 50 W horizontal and vertical
flame test methods
IEC 61730-2:2016, Photovoltaic (PV) module safety qualification – Part 2: Requirements for
testing

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SIST EN IEC 62788-5-1:2020
– 6 – IEC 62788-5-1:2020 © IEC 2020
IEC TS 61836, Solar photovoltaic energy systems – Terms, definitions and symbols
IEC 62788-1-2, Measurement procedures for materials used in photovoltaic modules –
Part 1-2: Encapsulants – Measurement of volume resistivity of photovoltaic encapsulants and
other polymeric materials
IEC TS 62788-2:2017, Measurement procedures for materials used in photovoltaic modules –
Part 2: Polymeric materials – Frontsheets and backsheets
IEC 62788-6-2, Measurement procedures for materials used in photovoltaic modules –
Part 6-2: General Tests – Moisture permeation testing with polymeric materials
ISO 62, Plastics – Determination of water absorption
ISO 1133-1, Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR)
of thermoplastics – Part 1: Standard method
ISO 4587, Adhesives – Determination of tensile lap-shear strength of rigid-to-rigid bonded
assemblies
ISO 6721-6, Plastics – Determination of dynamic mechanical properties – Part 6: Shear
vibration – Non-resonance method
ISO 11359-2, Plastics – Thermomechanical analysis (TMA) – Part 2: Determination of
coefficient of linear thermal expansion and glass transition temperature
ISO 11443, Plastics – Determination of the fluidity of plastics using capillary and slit-die
rheometers
ISO 15512, Plastics – Determination of water content
UL 746B, Polymeric materials – Long term property evaluations
UL 746C, Polymeric materials – Use in electrical equipment evaluations
ASTM D3835–08, Standard test methods determination of properties of polymeric materials by
means of a capillary rheometer
ASTM D6869–03, Standard test method for coulometric and volumetric determination of
moisture in plastics using the Karl Fischer reaction (the reaction of iodine with water)
ASTM D7191–10, Standard test method for determination of moisture in plastics by relative
humidity sensor
3 Terms,definitions and symbols
For the purposes of this document, the terms and definitions given in IEC TS 61836 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp

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SIST EN IEC 62788-5-1:2020
IEC 62788-5-1:2020 © IEC 2020 – 7 –
3.1 Terms and definitions
3.1.1
edge seal
polymeric material designed to be placed between two impermeable (or with extremely low
permeability) frontsheet and backsheet materials to restrict moisture ingress from the sides
3.1.2
Fickian
material for which the diffusivity is constant, independent of the concentration of the permeant
within the experimental uncertainty
3.2 Symbols
t time required for an edge seal to reach 10 % of its equilibrium water vapour
10 %
transmission rate [h]
-0,5
K 10 % moisture ingress breakthrough proportionality constant [cm·h ]
10 %
-0,5
K Arrhenius prefactor for K [cm·h ]
o10 % 10 %
-0,5
Ea Arrhenius activation energy for K [cm·h ]
K10 % 10 %
X edge seal film thickness [mm]
2
D Fickian diffusivity at a given temperature [cm /s]
2
D Arrhenius prefactor for diffusivity [cm /s]
o
Ea Arrhenius activation energy for diffusivity [kJ/mol]
D
3
S maximum absorption of moisture in a material in equilibrium with liquid water [g/cm ]
3
S irreversible absorption capacity of moisture in a material [g/cm ]
IR
3
S Arrhenius prefactor for solubility [g/cm ]
o
Ea Arrhenius activation energy for solubility [kJ/mol]
S
-2 -1
P permeability [g·mm·m ·day ]
-2 -1
P Arrhenius prefactor for permeability [g·mm·m ·day ]
o
Ea Arrhenius activation energy for permeability [kJ/mol]
p
4 Recommended tests
4.1 General
This document is intended to be used as a guideline for presenting edge seal data. When the
properties outlined in this document are reported, they shall be reported as measured using the
outlined methods. A datasheet may include more data, or less data, than the list of tests
outlined. The tests outlined are recommendations only.
4.2 Moisture permeation properties
4.2.1 Moisture breakthrough time
1/2
10 % moisture ingress breakthrough proportionality constant [K , (X = K · t )] at
10 % 10 % 10 %
(85 ± 2) °C as determined in IEC 62788-6-2. Include activation energy if available. For a Fickian
1/2
material, K = 3,89 · D .
10 %
4.2.2 Fickian materials
Permeability (P) at (85 ± 2) °C steady state. Include activation energy (Ea ) if available.
p

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SIST EN IEC 62788-5-1:2020
– 8 – IEC 62788-5-1:2020 © IEC 2020
If the material is Fickian, report the diffusivity (D) at (85 ± 2) °C and activation energy for
diffusivity (Ea ) as determined from IEC 62788-6-2. Also indicate the temperature range over
D
which the diffusivity was measured.
If the material is Fickian, report the solubility (S) at (85 ± 2) °C and activation energy for
solubility as determined from IEC 62788-6-2. Also indicate the temperature range over which
the solubility was measured.
4.2.3 Non-Fickian materials
For non-Fickian materials, report the solubility (S) at (85 ± 2) °C using ISO 62, ASTM D7191-10,
ASTM D6869-03, or ISO 15512. Samples should be equilibrated at temperature while placed in
a sealed container with water, but not in contact with the water. The use of sufficient sample
equilibration time shall be verified by testing multiple samples at progressively longer times.
Samples should be tested immediately after removal from the container because of the potential
for the evaporation of moisture.
If applicable, also report the irreversible solubility (S ) by measuring the reversible absorption
IR
of a sample saturated at (85 ± 2) °C using ISO 15512, ASTM D7191-10 or ASTM D6869-03 and
subtracting that from S.
NOTE If the sample contains desiccant, ASTM D7191-10 and ASTM D6869-03 may not work because the water
may be irreversibly adsorbed. Furthermore, for molecular sieve-type desiccants, the time required to remove trace
amounts of water fully from the desiccant can severely limit the accuracy of these methods and the temperature
required to dry the samples can cause other volatile molecules to evaporate.
4.3 Electrical properties
4.3.1 Dielectric strength of the film
Perform a measurement of dielectric strength in accordance with IEC 60243-2 for a DC test.
This shall conform to IEC TS 62788-2:2017, 4.5.1 and IEC TS 62788-2:2017, Annex C. Use a
material thickness that is useable at a practical voltage, which is rarely greater than 100 kV DC,
for the testing equipment. The surfaces of the samples shall be free of volumetric defects (e.g.
bubbles, voids or foreign particles) and be made smooth, which may require curing according
to the manufacturer’s specifications.
Measure and report values before and after saturation with water to duplicate conditions after
the desiccant is spent. For the saturated samples, precondition at (85 ± 2) °C and (85 ± 5) %
relative humidity (RH) prior to testing. Allow materials to equilibrate at room temperature prior
to testing. Ensure that saturated samples do not dry out before testing, but one may remove
any water droplets from the surface. The amount of time needed for equilibration will be
determined by the
...