IEC 63211-2-21:2025

IEC 63211-2-21 ®
Edition 1.0 2025-06
INTERNATIONAL
STANDARD
Durability test methods for electronic displays –
Part 2-21: Environmental tests – Test methods for heat and humidity
ICS 31.120  ISBN 978-2-8327-0394-6

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– 2 – IEC 63211-2-21:2025 © IEC 2025
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references. 7
3 Terms, definitions and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 8
4 Standard conditions . 8
4.1 Standard reference atmosphere . 8
4.2 Standard atmospheric conditions for measurements and tests . 8
4.3 Recovery conditions . 8
4.4 Tolerance of operation fluctuations . 9
5 Test equipment . 9
5.1 Test chamber . 9
5.2 Mounting the test specimen . 9
6 Test specimens . 9
7 Test conditions . 10
7.1 General . 10
7.2 High temperature . 10
7.2.1 Purpose . 10
7.2.2 High temperature storage (HTS) . 10
7.2.3 High temperature operation (HTO) . 10
7.3 Low temperature . 10
7.3.1 Purpose . 10
7.3.2 Low temperature storage (LTS) . 11
7.3.3 Low temperature operation (LTO) . 11
7.4 Damp heat . 11
7.4.1 Purpose . 11
7.4.2 Damp heat, steady state, storage (DHSS) . 11
7.4.3 Damp heat, steady state, operation (DHSO) . 11
7.4.4 Damp heat, cyclic (DHC) . 12
7.5 Composite temperature and humidity cyclic (CTHC) . 12
7.5.1 Purpose . 12
7.5.2 Temperature, humidity, duration time and temperature change . 12
7.6 Temperature change . 13
7.6.1 Purpose . 13
7.6.2 Specified change rate of temperature (SCRT) . 13
7.6.3 Rapid change of temperature (RCT) . 13
8 Test procedure . 13
8.1 General . 13
8.2 Test procedures of temperature and humidity test . 14
8.3 Test procedures of temperature and humidity cyclic test . 16
8.4 Test procedures of temperature change test . 18
Annex A (informative) Recommended test conditions for different display technologies . 20
Bibliography . 23

Figure 1 – Temperature profile of HTS, HTO . 14
Figure 2 – Temperature profile of LTS, LTO . 15
Figure 3 – Temperature and humidity profile of DHSS, DHSO . 15
Figure 4 – Temperature and humidity profile of DHC . 17
Figure 5 – Temperature and humidity profile of temperature and humidity cycle without
followed by exposure to cold . 17
Figure 6 – Temperature and humidity profile of temperature and humidity cycle
followed by exposure to cold . 18
Figure 7 – Temperature profile of SCRT . 19
Figure 8 – Temperature profile of RCT . 19

Table A.1 – Test conditions for different display technologies . 20

– 4 – IEC 63211-2-21:2025 © IEC 2025
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DURABILITY TEST METHODS FOR ELECTRONIC DISPLAYS –

Part 2-21: Environmental tests –
Test methods for heat and humidity

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
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IEC 63211-2-21 has been prepared by IEC technical committee 110: Electronic displays. It is
an International Standard.
The text of this International Standard is based on the following documents:
Draft Report on voting
110/1742/FDIS 110/1760/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts in the IEC 63211 series, published under the general title Durability test
methods for electronic displays, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
– 6 – IEC 63211-2-21:2025 © IEC 2025
INTRODUCTION
All documents developed in IEC TC 110 that are concerned with the durability of electronic
displays refer to a set of methods and procedures that are similar to each other, or sometimes
even identical. This document is intended to identify these methods and to describe them as a
reference for forthcoming standards to make the work of the involved experts more efficient and
to avoid duplication of efforts.
Environmental tests for different display technologies are covered in specific standards,
including IEC 62715-6-2, IEC 62679-4-2, IEC 62341-5, IEC 62908-13-10, and IEC 61747-10-2.
They were originally created using the IEC 60068 series as a reference, in which some
modifications were introduced to be suitable for electronic displays. However, the relevance of
environmental test largely depends on the application and intended use of the display, rather
than the technology utilized. Therefore, the creation of a comprehensive, technology-agnostic
IEC standard for environmental test of electronic displays is proposed. Such a standard would
facilitate more application-centric and use-case focused test protocols, resulting in a more
thorough assessment of electronic displays under various environmental conditions.
This document has been prepared for the following objectives:
a) to avoid unnecessary deviations;
b) to avoid inefficient discussions and documents in multiple working groups;
c) to follow ISO/IEC Directives Part 2:2021, 5.7 (Avoidance of duplication and unnecessary
deviations).
This document relates to the common durability test methods applicable in the field of electronic
displays, which can overlap with some of the parts of existing TC 110 documents that describe
the durability test methods of individual technologies, such as LCD, OLED, PDP and others.
This document is intended to be used as the reference document in future standards and in
revisions of existing ones. The existing standards will be revised in their maintenance time to
refer to this document to the largest extent possible.

DURABILITY TEST METHODS FOR ELECTRONIC DISPLAYS –

Part 2-21: Environmental tests –
Test methods for heat and humidity

1 Scope
This part of IEC 63211 provides test methods of the environmental tests for resistance to heat
and humidity. This part of IEC 63211 is used to evaluate the ability of electronic displays to
resist environmental damage. This document applies to electronic displays.
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 60068-1, Environmental testing – Part 1: General and guidance
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60068-1 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1.1
operation control point
set point for equilibrium conditions measured at sensor location(s) in an exposure device
3.1.2
operation fluctuations
positive and negative deviations from the setting of the sensor at the operation control set point
during equilibrium conditions in a laboratory-accelerated weathering device

– 8 – IEC 63211-2-21:2025 © IEC 2025
3.2 Abbreviated terms
CTHC composite temperature and humidity cyclic
DHC damp heat, cyclic
DHSO damp heat, steady state, operation
DHSS damp heat, steady state, storage
EPD electronic paper display
FDD flexible display device
HTO high temperature operation
HTS high temperature storage
LCD liquid crystal display
LTO low temperature operation
LTS low temperature storage
OLED organic light emitting diode
RCT rapid change of temperature
SCRT specified change rate of temperature
TID touch and interactive display
4 Standard conditions
4.1 Standard reference atmosphere
The following conditions are applied:
– temperature: 25 °C
– relative humidity: 50 % RH
– air pressure: 101,3 kPa
When different environmental conditions are used, they shall be noted in the report.
4.2 Standard atmospheric conditions for measurements and tests
All tests and measurements shall be carried out under standard atmospheric conditions.
– temperature: 15 °C to 35 °C
– relative humidity: 25 % RH to 85 % RH, where appropriate
– air pressure: 86 kPa to 106 kPa
4.3 Recovery conditions
The recovery conditions shall be in accordance with standard atmospheric conditions in 4.2.
The electronic displays shall remain the same under standard atmospheric conditions for
recovery for a period adequate for the attainment of temperature stability, with a minimum of
1 h.
If required by the relevant specification, the specimen shall be switched on or loaded during the
recovery period, in order to measure the properties of specimen after test.
If the standard conditions given above are not appropriate for the device to be tested, the
relevant specification may call for other recovery conditions.
During the recovery process, there shall be no condensation on the specimen surface.

4.4 Tolerance of operation fluctuations
For temperature control, the 24 h average of the operation fluctuations shall be within ±1,0 °C
of aim, and the operation fluctuations shall be within ±3,0 °C of aim.
For relative humidity control, the 24 h average of the operation fluctuations shall be within
±2,0 % RH of aim, and the operation fluctuations shall be within ±6,0 % RH of aim.
The transition time shall not be accounted in the aforementioned tolerance, and it shall not be
more than 1 h after count started.
5 Test equipment
5.1 Test chamber
Test chamber conditions are as follows.
a) Sensing devices shall be located in the working space to monitor the temperature and
humidity.
b) The low temperature, the high temperature, the relative humidity and the change rate
required for test shall be maintained.
c) The working space in the chambers shall be under uniform test conditions.
d) Condensed water shall be continuously drained from the chamber and not used again unless
it has been required. No condensed water from the walls and roof of the test chamber shall
fall on the specimens.
e) For rapid changes of temperature, the chamber either shall have the ability to rapidly change
between low and high temperature or it shall be possible to move test specimens between
two chambers with minimal exposure time.
5.2 Mounting the test specimen
Unless otherwise specified in the relevant specification, the thermal conduction of the mounting
shall be low, in such a way that for practical purposes the specimen is thermally isolated. When
testing several specimens simultaneously, they shall be placed so that free circulation is
provided between the specimens, circulation is provided between the specimens and chamber
surface.
6 Test specimens
The specimens shall be introduced to the chamber at standard atmospheric conditions and in
the unpacked, switched-off, ready-for-use state. For composite temperature and humidity cyclic
(CTHC), the specimens shall be subjected to the “assisted drying” conditions specified in
IEC 60068-1 (55 °C with a relative humidity not exceeding 20 %) for a period of 24 h prior to
the first cycle of damp heat test. For damp heat, cyclic (DHC), the specimens shall be stabilized
at a temperature of 25 °C and the relative humidity shall be increased to not less than 95 % RH.
Take precautions to ensure condensation does not impair the functionality of the specimens.

– 10 – IEC 63211-2-21:2025 © IEC 2025
7 Test conditions
7.1 General
The environmental test method is often used as one of several endurance test methods. When
the test method defined in this document is used as one of these endurance test methods,
revi
...