IEC TS 62876-2-1:2018

Nanotechnology - Reliability assessment - Part 2-1: Nano-enabled photovoltaic devices - Stability test

IEC TS 62876-2-1:2018 establishes a general stability testing programme to verify the stability of the performance of nanomaterials and nano-enabled photovoltaic devices (NePV) devices. These devices are used as subassemblies for the fabrication of photovoltaic modules through a combination with other components. This testing programme defines standardized degradation conditions, methodologies and data assessment for technologies. The results of these tests define a stability under standardized degradation conditions for quantitative evaluation of the stability of a new technology. The procedures outlined in this document were designed for NePV, but can be extended to serve as a guideline for other photovoltaic technologies as well.

General Information

• Status: Published
• Publication Date: 28-Aug-2018
• ICS: 07.120 - Nanotechnologies
• ICS: 27.160 - Solar energy engineering
• Technical Committee: TC 113 - Nanotechnology for electrotechnical products and systems
• Drafting Committee: PT 62876-2-1 - TC 113/PT 62876-2-1
• Current Stage: PPUB - Publication issued
• Start Date: 29-Aug-2018
• Completion Date: 13-Sep-2018

Standards Content (Sample)

IEC TS 62876-2-1 ®
Edition 1.0 2018-08
TECHNICAL
SPECIFICATION
Nanotechnology – Reliability assessment –
Part 2-1: Nano-enabled photovoltaic devices – Stability test

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IEC TS 62876-2-1 ®
Edition 1.0 2018-08
TECHNICAL
SPECIFICATION
Nanotechnology – Reliability assessment –

Part 2-1: Nano-enabled photovoltaic devices – Stability test

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 07.120; 27.160 ISBN 978-2-8322-5981-8

– 2 – IEC TS 62876-2-1:2018 © IEC 2018
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 9
2 Normative references . 9
3 Terms, definitions and abbreviated terms . 10
3.1 Terms and definitions . 10
3.2 Abbreviated terms . 11
4 General requirements . 11
4.1 Device . 11
4.2 Tests . 12
4.2.1 General . 12
4.2.2 Quantity of specimens . 14
4.2.3 Sequence . 14
4.2.4 Equipment specifications . 14
4.2.5 Test methods . 14
4.3 Measurements . 15
4.3.1 General . 15
4.3.2 Conditioning . 15
4.3.3 Visual inspection . 16
4.3.4 Data collection . 16
4.3.5 Pass/fail criteria . 16
5 Test methods . 17
5.1 ST1 – Dry heat . 17
5.1.1 Purpose . 17
5.1.2 Temperature/humidity . 17
5.1.3 Data logging . 17
5.1.4 Output . 17
5.1.5 Required equipment . 17
5.2 ST2 – UV exposure . 17
5.2.1 Purpose . 17
5.2.2 Radiation source. 17
5.2.3 Temperature/humidity . 18
5.2.4 Data logging . 18
5.2.5 Output . 18
5.2.6 Required equipment . 18
5.3 ST3 – Damp heat . 18
5.3.1 Purpose . 18
5.3.2 Procedure . 18
5.3.3 Temperature/humidity . 18
5.3.4 Data logging . 18
5.3.5 Output . 19
5.3.6 Required equipment . 19
5.4 ST4 – Light exposure . 19
5.4.1 Purpose . 19
5.4.2 Light source . 19
5.4.3 Devices and load condition . 19

5.4.4 Temperature . 19
5.4.5 Humidity at ambient conditions . 19
5.4.6 Data logging . 19
5.4.7 Output . 20
5.4.8 Required equipment . 20
5.5 ST5 – Outdoor exposure . 20
5.5.1 Purpose . 20
5.5.2 Locations . 20
5.5.3 Solar irradiance . 20
5.5.4 Devices . 20
5.5.5 Temperature . 20
5.5.6 Load condition . 20
5.5.7 Humidity/wind . 21
5.5.8 Data logging . 21
5.5.9 Output . 21
5.5.10 Required equipment . 21
5.6 ST6 – Laboratory weathering . 21
5.6.1 Purpose . 21
5.6.2 Temperature/humidity/light . 21
5.6.3 Devices . 21
5.6.4 Load condition . 22
5.6.5 Data logging . 22
5.6.6 Output . 22
5.6.7 Required equipment . 22
5.7 ST7 – Thermal cycling . 22
5.7.1 Purpose . 22
5.7.2 Temperature/humidity . 22
5.7.3 Data logging . 22
5.7.4 Output . 23
5.7.5 Required equipment . 23
6 Report . 23
Annex A (informative) Overview of common failure modes – Failure mode and known
failure mechanisms for nano-enabled photovoltaic devices . 25
Annex B (informative) Stability test temperature choice – How to choose the best
temperature for stability testing of new technologies . 26
Annex C (informative) Correspondence between ISOS protocols and the stability test
for nano-enabled photovoltaic devices outlined in this document . 27
Bibliography . 30

Figure 1 – Generic representation of a device under test during IV-characterization . 8
Figure 2 – Overview of stresses that photovoltaic devices are exposed to in service
environments . 12
Figure 3 – General stability test procedure . 13
Figure 4 – Overview of the stability assessment tests that are recommended for
standard testing in order to assess the stability of NePV . 14
Figure 5 – Plot of the temperature cycle to be used for thermal cycling. . 23

Table 1 – Summary of the stresses utilized in this document . 13

– 4 – IEC TS 62876-2-1:2018 © IEC 2018
Table 2 – Summary overview of the relevant test methods and main control
parameters. . 15
Table 3 – Exposure parameters according to ISO 4892-2:2013, Table 3, cycle 1. . 21
Table C.1 – Overview of the tests described in this document, in comparison to the
tests recommended in ISOS 2009 and ISOS 2011 . 28

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
NANOTECHNOLOGY – RELIABILITY ASSESSMENT –

Part 2-1: Nano-enabled photovoltaic devices – Stability test

FOREWORD
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Technical Specifications are subject to review within three years of publication to decide
whether they can be transformed into International Standards.
IEC 62876-2-1, which is a Technical Specification, has been prepared by IEC technical
committee113: Nanotechnology for electrotechnical products and systems.

– 6 – IEC TS 62876-2-1:2018 © IEC 2018
The text of this Technical Specification is based on the following documents:
Enquiry draft Report on voting
113/334/DTS 113/421/RVDTS
Full information on the voting for the approval of this Technical Specification 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.
The committee has decided that the contents of this document will remain unchanged until the
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the specific document. At this date, the document will be
• transformed into an International Standard,
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

INTRODUCTION
Nano-enabled photovoltaics (NePV) is a novel format of photovoltaic technology that can be
manufactured in large-area, flexible, thin sheets through solution processing or vapour
deposition. Many of the materials involved are nanomaterials and organic semiconductors.
They improve the conversion of sunlight into free electrons and support the extraction of the
electrons out of the device. Furthermore, nanomaterials are used as boundary layers and act
as protective coatings to increase the stability of the PV device. NePV has the potential to
provide low-cost renewable energy due to relatively inexpensive, high-throughput
manufacturing and low material costs, as a result of the use of low-cost flexible polymeric
substrates and packaging films [1]. In addition, NePV is expected to enable new products due
to its light weight, flexibility, ability to adapt and tune colour appearance and good efficiency
at low light levels, which is conducive to indoor use. Due to these properties NePV is
attracting more attention from a variety of groups with a view to improving the efficiency and
stability, which has resulted in significant efficiency gains through achievements in materials
engineering and process optimization. Concerning stability, however, improvements have not
been evident and have not been demonstrated, since standardized testing methods do not
exist. In order to commercialize NePV, its stability must be addressed and means for properly
comparing stability need to be developed.
Within the scope of this document, NePV refers to photovoltaic devices made from nano-sized
material entities, involving a combination of organic and inorganic components and hard and
soft matter, sometimes including liquid electrolytes, which are combined using low-cost
preparation methods mainly by low-temperature solution processing. The developments of
these types of solar cells are primarily through four main directions: organic polymers or small
molecules (OPV), dye sensitized solar cells (DSSC), organic/inorganic hybrid solar cells and
quantum dot based solar cells. The procedures outlined in this document were designed for
NePV, but may be extended to serve as a guideline for early stability assessment for new
materials or processes for other photovoltaic technologies as well.
Stability assessment standards define the conditions for a set of stress tests, which address
isolated stress factors that can lead to failure in a service environment, in order to allow
developers to test under repeatable conditions and to quantitatively compare the stability of
photovoltaic devices subjected to these conditions. Several such stability assessment
protocols have been proposed by the International Summit on OPV Stability (ISOS) of the
OPV community [2,3]. The test conditions defined in this document are based on the ISOS
protocol by selecting and modifying the conditions so that they are applicable to a range of
NePV devices. True reliability prediction and quantification, however, requires significantly
more extensive testing and is not within the scope of this document.
The objectives of this document are to specify the requirements for a general stability
assessment standard (SAS) for NePV intended to be used in but not limited to outdoor
environments; give direction to developers and engineers developing NePV devices, to guide
test laboratories on testing, and to allow for a quantitative stability comparison between
different technologies. It is not intended that the requirements specified in this document are
to be used for device-type approval or certification. This document simply provides a set of
tests for stability assessment and establishes the minimum reporting requirements in order to
guide the community through a process of technology improvement by achieving comparable
measurements and allowing improvement in device stability to be measured in a qualified and
comparable methodology. More specific test conditions for specific devices and/or for specific
applications should be developed separately in the future.
The general procedure for the recommended stability testing procedure is to measure device
performances before and at certain intervals after applying well defined stresses to NePV
devices, in order to track the performance changes due to the applied stresses. Not all
recommended tests or stress conditions need to be performed at all stages of development. In
the early stages of development a subset of tests which are relatively easy to implement,
e.g. dry-heat, damp-heat and light exposure, should be performed first to achieve a first
information about the general stability of the tested system. As development of a particular
technology progresses and the technology matures, it is recommended to add more

– 8 – IEC TS 62876-2-1:2018 © IEC 2018
sophisticated tests as deemed necessary. Retesting at later stages for regular process control
and materials monitoring should also be considered to identify problems. The tests single out
certain stress factors that are expected to frequently occur during outdoor exposure. In this
document each of the tests is intended to be performed on a new set of devices in order to
determine the most detrimental stress factors and aid in an optional failure mode analysis.
Sequential tests in various conditions may be performed, but the results are expected to be
difficult to interpret. To include the effect of multiple and varied stresses, a laboratory
weathering test was adapted and included.
NePV will incorporate many polymeric materials such as binders for nano-materials,
substrates, adhesives and packaging materials, which may have a strong interaction with the
NePV photovoltaic active layers of the devices under test, and may therefore affect the
stability of the device as a whole. To address this, the stability tests in this document are
closely related to those used in artificial weathering for polymers. The stability tests outlined
in this document could be a component of an exhaustive failure analysis in order to identify
the causes of performance losses, which can be the result of many different issues.
The procedures described in this document are focused but not limited to nano-enabled PV
devices. The document outlines minimal equipment and procedural practices. Stability should
always be regarded as a system property. As layers or materials in the system are changed
(including in the packaging), retesting will be necessary to ensure that stability is not affected
in a detrimental manner.
This document makes no specific recommendation about the materials and device structures
to be tested, and can be applied to a wide variety of systems. A generic picture of a device
under test is shown in Figure 1.

Figure 1 – Generic representation of a device under test
during IV-characterization
This document is meant to be a general document that can be applied to all NePV devices. As
such, it is not intended to be used as a standard for assembled photovoltaic modules. The
stress tests are specific and explicitly defined to establish consistency of test procedures and
reporting of reliability information.

NANOTECHNOLOGY – RELIABILITY ASSESSMENT –

Part 2-1: Nano-enabled photovoltaic devices – Stability test

1 Scope
This part of IEC 62876, which is a Technical Specification, establishes a general stability
testing programme to verify the stability of the performance of nanomaterials and nano-
enabled photovoltaic devices (NePV) devices. These devices are used as subassemblies for
the fabrication of photovoltaic modules through a combination with other components. This
testing programme defines standardized degradation conditions, methodologies and data
assessment for technologies. The results of these tests define a stability under standardized
degradation conditions for quantitative evaluation of the stability of a new technology. The
procedures outlined in this document were designed for NePV, but can be extended to serve
as a guideline for other photovoltaic technologies as well.
NOTE 1 The tests in this document are selected with outdoor use in mind, and as such represent isolated stress
factors that devices will be exposed to in outdoor environments. For indoor environments, the stresses faced by the
devices in operation are significantly less severe, and not all tests will be applicable. Despite this, the suggested
tests provide a means of tracking stability improvements and can provide valuable data during device development.
NOTE 2 The performance of devices will be evaluated before and after the application of the stress tests. The
efficiency characterization methods for NePV have not been fully established at present. In the text, notes are
therefore added regarding the efficiency characterization. The notes particularly address issues to be discussed in
the future for applications such as indoor use, or devices with a slow response or uncommon spectral responses
such as tandem cells.
NOTE 3 The scope does not include photovoltaic modules, i.e. the final product. It is only intended to test the
technology.
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.
ISO 4892-1, Plastics – Methods of exposure to laboratory light sources – Part 1: General
guidance
ISO 4892-2:2013, Plastics – Methods of exposure to laboratory light sources – Part 2: Xenon-
arc lamps
ISO 9370, Plastics – Instrumental determination of radiant exposure in weathering tests –
General guidance and basic test method
ISO 877-1, Plastics – Methods of exposure to solar radiation – Part 1: General guidance
ISO/IEC 17025, General requirements for the competence of testing and calibration
laboratories
IEC 60904-1, Photovoltaic devices – Part 1: Measurement of photovoltaic current-voltage
characteristics
IEC 60904-9, Photovoltaic devices – Part 9: Solar simulator performance requirements

– 10 – IEC TS 62876-2-1:2018 © IEC 2018
IEC 60068-2-2, Environmental testing – Part 2-2: Tests – Test B: Dry heat
IEC 60068-2-78, Environmental testing – Part 2-78: Tests – Test Cab: Damp heat, steady
state
3 Terms, definitions and abbreviated terms
NOTE A comprehensive nanotechnology vocabulary is under joint development in IEC TC 113 and ISO/TC 229.
The vocabulary is being published as different parts of the 80004 Technical Specification. This document is
harmonized with the terms and definitions of the 80004 Technical Specification at the time of publication and will
be kept harmonized during the maintenance of the document. Definitions not yet specified are taken from scientific
literature.
3.1 Terms and definitions
For the purposes of this document, the following terms and definitions 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
3.1.1
nano enabled photovoltaic device
NePV
photovoltaic device in which the conversion of light into electrical energy is enabled or
significantly enhanced by nanotechnology
Note 1 to entry Nano-enabled photovoltaics refers to photovoltaic devices and semi-finished products in which
one or more of the active light conversion materials are based on a nano-material or semiconductor. NePV includes
bulk-heterojunction photovoltaic devices made from organic polymers or small molecules, as well as dye-sensitized
solar cells and hybrid solar cells made from both organic and inorganic materials. NePV includes photovoltaic
devices made from inorganic nanoparticles as well.
3.1.2
device under test
DUT
representative device used in testing
Note 1 to entry Nano-enabled photovoltaic devices consist of multiple functional layers which are mechanically
and electrically connected or are applied (e.g by printing) on a flexible or rigid substrate. For test purposes,
samples are recommended to have dimensions that are representative of the technology and allow for a conclusion
that a technology can be produced on a larger scale. For this purpose, a suitable minimum aperture area of the
NePV devices used in the stability assessment is large enough to test area effects and minimize edge effects
(a recommended device area is approx.1 cm or larger in accordance with the standards for efficiency certification
of PV-devices). This document is intended to guide and facilitate the development of new technologies, and NePV
devices subjected to these tests are intended to be unpackaged or packaged semi-finished devices that are not
finished products for the end user.
3.1.3
IV-characterization
measurement of the current-voltage characteristic
Note 1 to entry:
a) Artificial irradiation light sources other than terrestrial solar light are generally used for characterization.
b) For irradiation light sources other than specified in IEC 60904, the total light intensity can be properly
determined from the absolute device spectral response and irradiation light spectrum. It is recommended that
the irradiation light spectrum and absolute device spectral response is documented in the test report. [1]
c) Due to the nature of NePV as defined in 3.1.1, specifically designed algorithms for IV-characterization may be
applied, e.g. [2]. It is recommended that the algorithms are documented in detail in the test report.

3.1.4
conditioned efficiency
light conversion efficiency measured for a device after the conditioning procedure has been
applied
Note 1 to entry: A conditioning may need to be applied to devices prior to IV-characterization in order to achieve
reproducible efficiency measurements. The conditioning procedure outlined in this document is recommended to be
followed to ensure that the device does not change its efficiency during the measurement.
3.1.5
initial conditioned efficiency
efficiency measured for a device after the conditioning procedure has been applied prior to
exposure to stress testing
3.1.6
t
time until the conditioned efficiency has reached 80 % of the initial conditioned efficiency
Note 1 to entry t refers to the stability criterion that is used to define the end of testing. It is the time that the
DUT is subjected to the accelerated ageing conditions in the stress test until its stabilized efficiency has reached
80 % of the initial stabilized efficiency. Recommended duration for the accelerated stress tests is until either t or
a satisfactory exposure level representative for use conditions has been reached.
3.1.7
maximum power point
MPP
point in the IV-characteristic of a photovoltaic device where the product of current and voltage,
the output power, achieves its maximum value
[SOURCE: IEC TS 61836:2007, 3.4.42 c), modified.]
3.1.8
visual inspection
procedure to detect any visual defects in the specimen
3.1.9
resistive temperature detector
RTD
temperature measurement device that utilizes the temperature based change in resistance in
order to measure temperature
EXAMPLE Commercially available PT100 detectors.
3.2 Abbreviated terms
t time to reach 80 % of the initial stabilized efficiency
DUT device under test
MPP maximum power point
RTD resistive temperature detector
SAS stability assessment standard
NePV nano-enabled photovoltaics
4 General requirements
4.1 Device
The specific NePV device to which this document relates is typically an individual cell or a
subassembly which will be used by a module assembler to fabricate the end product to be
sold to the end user. For the purpose of this stability assessment procedure the product does

– 12 – IEC TS 62876-2-1:2018 © IEC 2018
not need to be clearly defined. The purpose of this document is to assess the stability of the
technology. The test samples shall be selected randomly from a larger population of samples
such that the DUTs are representative for the ensemble of test devices. The physical size of
the samples shall be such that the DUTs are large enough to be susceptible to relevant
degradation mechanisms.
Regarding the scope of this document, it is assumed that the device is a subassembly.
4.2 Tests
4.2.1 General
All the tests in this document fall into the class of accelerated stability tests. These tests are
designed to expose the DUTs to specific well-defined and reproducible stress factors that
accelerate critical failure mechanisms. Being able to quantify the response of the devices to
the stresses at an early development stage allows for efficient development cycles to improve
the stability of the devices under laboratory conditions.
In a later service environment a technology will face different stresses based on the final
application that is chosen. To evaluate the stability, a suitable selection of relevant stress
factors is important in order to reflect realistic conditions. These stress factors are not so
harsh that they will disqualify a technology too early, but are harsh enough to identify
weaknesses in a technology and to provide a means to quantify improvement in a
development process. An overview of typical stress factors that photovoltaic devices are
exposed to is shown in Figure 2.

Figure 2 – Overview of stresses that photovoltaic
devices are exposed to in service environments
General stability testing is performed by repeated measurements of the performance of DUTs
before and after exposure to a stress or a combination of stresses for a period of time. A
typical procedure is shown in Figure 3. After initial characterization the device is submitted to
the stress environment for a regular time interval. After the exposure interval the device is
conditioned for measurement, characterized and then re-exposed. This document provides
certain combinations of suggested stresses so that appropriate stress conditions may be
selected. In addition it defines the procedures and equipment requirements that are necessary
to perform reliable and reproducible stability measurements.
In selecting the appropriate type and severity of stress, knowledge about the most frequent
failure modes and failure mechanisms for nano-enabled PV devices is required. For guidance,
Annex A lists the most important failure modes for this PV device type. In Annex B the most
common failure mechanisms for PV devices are compiled.
Annex C provides guidance for choosing an appropriate temperature for the application of the
selected stress factors.
Figure 3 – General stability test procedure
The stress tests that are recommended are combinations of a limited number of well-defined
stresses. Table 1 gives an overview of recommended values for the typical stresses which are
encountered in many testing protocols.
Table 1 – Summary of the stresses utilized in this document
Stress Typical values
Temperature (T) Ambient 45 °C 65 °C 85 °C Thermal cycle
−40 °C to 85 °C
Humidity (H) Ambient 0 % RH 50 % RH 85 % RH
Light (L) No(dark) Outdoor Solar simulator Lamp UV
(AM1.5,
1 000 W/m )
Misc. (M) Atmospheric Mechanical
effects (pressure, shear)
Any combination is possible. For acceleration of degradation, however, appropriate
combinations should be chosen, which reflect the expected service environment in which the
technology is likely to be used later. In addition, it is desirable to have a measurable
degradation effect, i.e. the degradation should not be too small which might be the case if too
small a measurement area has been chosen for evaluation. For example, test conditions
which cause more than 20 % degradation of the performance in the evaluation period are
considered to be appropriate.
For photovoltaic devices a number of suggested tests have evolved. An overview of the
suggested tests for standard stability testing is shown in Figure 4, in the order of increasing
complexity.
– 14 – IEC TS 62876-2-1:2018 © IEC 2018

Figure 4 – Overview of the stability assessment tests that are recommended for
standard testing in order to assess the stability of NePV
4.2.2 Quantity of specimens
All stability testing shall be performed on statistically relevant sample groups. While the
sample groups should generally be chosen as large as possible, a minimum group size is
defined to be of five samples for each of the tests performed in the case of small samples. For
larger devices (> 25 cm ) testing may also be performed on smaller groups.
4.2.3 Sequence
The tests are not intended to be performed in sequence. DUTs can only be subjected to one
particular test, so that several of the stress tests can be performed in parallel to expedite the
testing. To fully assess stability it is recommended that groups of DUTs are subjected to each
of the tests. At the initial stages, testing should be performed with the less complex tests.
Once acceptable stability levels are achieved, the more complex tests should be performed
on new groups of DUTs. Acceptable stability levels are not defined in this document and
should be determined by the manufacturer.
4.2.4 Equipment specifications
In order for the testing to be acceptable all tests shall be performed in qualified and calibrated
equipment that allows for the monitoring of the environmental conditions.
Detailed specifications are listed in the relevant subclauses or should be taken from the
referenced standards.
4.2.5 Test methods
All the test methods recommended in this document, with the exception of outdoor exposure,
fall into the class of “accelerated degradation tests”. These tests expose the DUTs to a
selected but tightly controlled set of stress parameters in highly specialized testing equipment,
in order to perform quantitative stability testing. Since in an outdoor service environment a
device is always exposed to a combination of a multitude of these stresses, it is generally
recommended to perform additional outdoor weathering of the devices in order to observe
whether the failure mechanisms in the outdoor environment are similar to the ones observed
in laboratory stability testing, and thus to validate the laboratory tests. An overview of all the
recommended tests with the main control parameters is shown in Table 1.

In order to assess the stability of NePV devices it is necessary to perform a number of
accelerated degradation and environmental tests. Table 2 gives an overview of the
recommended tests within the scope of this document.
Table 2 – Summary overview of the relevant test methods and main control parameters.
Test ID and description
ST1 ST2 ST3 ST4 ST5 ST6 ST7
Parameter
Dry heat UV Damp Light Outdoor Laboratory Thermal
exposure heat exposure exposure weathering cycling
Light None UV None Daylight, Ambient Daylight, None
(600 to (600 to
2 2
1 000) W/m 1 000) W/m
Temperature 45 °C 65 °C 45 °C 65 °C Ambient 38 °C −40 °C
to +85 °C
a
65 °C 65 °C
a
85 °C 85 °C
Humidity Ambient Ambient 85 % RH Ambient Ambient 50 % RH/ Ambient
water spray
Environment Oven UV chamber Climate Light soak Outdoor Weathering Climate
chamber chamber instrument chamber
Load None None None Passive or Passive or Passive or None
Active, MPP Active, MPP Active, MPP
a
Underl
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