ISO 9211-3:2024

International
Standard
ISO 9211-3
Third edition
Optics and photonics — Optical
2024-02
coatings —
Part 3:
Environmental durability
Optique et photonique — Traitements optiques —
Partie 3: Durabilité environnementale
Reference number
© ISO 2024
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Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General information for use . 2
4.1 Environmental test code .2
4.2 Standard categories of use .2
4.2.1 General .2
4.2.2 Category A .3
4.2.3 Category B .3
4.2.4 Category C .4
4.2.5 Category D .4
4.2.6 Category O .5
4.3 General use case .6
4.4 Operating and storage conditions .6
4.5 Temperature conditions .6
4.6 Influence of the substrate .6
4.7 Cemented coatings .6
5 Indications on drawings . 6
5.1 Standard categories of use .6
5.2 General use case .6
5.2.1 General .6
5.2.2 Direct description.7
5.2.3 Tabular description .7
Annex A (normative) Environmental tests for optical coatings . 8
Annex B (informative) Implementation of test sequence for Category of use O . 14
Bibliography .15

iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee [or Project Committee] ISO/TC 172, Optics and
photonics, Subcommittee SC 3, Optical materials and components.
This third edition cancels and replaces the second edition (ISO 9211-3:2008), which has been technically
revised.
The main changes are as follows:
— Included ISO 9211-2 in bibliography.
— Add new section that explains the test code notation to use when specifying a coating environmental
durability test.
— Remove previous Annex A and move test sequence tables for standard categories into relevant sections.
— Update notation for standard test sequence tables to include conditioning method and degree of severity
test code notation.
— Clarify that category O is for non-standard test sequences that are also similar to other standard
categories of use.
— Add new section for a general use case when specifying coating environmental durability tests and the
sequence they follow. This is used for test sequences that are not similar to any of the standard categories
of use.
— Add statement that if specifying a temperature requirement for a coating, this notation is described in
ISO 9211-2.
— Add new Annex A that includes the previously shown Table 1.
— Update previous Table 1 to include conditioning method and degrees of severity test code notation.
— Add new relevant degrees of severity from ISO 9022-2/Amd.1 and ISO 9022-4/Amd.1.

iv
— Add conditioning methods and degrees of severity shown in ISO 9211-5 to ISO 9211-8 not listed previously.
— Clarify descriptions in previous Table 1 to match what is listed in the conditioning method table for each
test.
— Separate solvent solubility line in previous Tables A.2, A.3 and A.4 to two lines, separating acetone and
ethanol.
— Add new Annex B explaining how to use category O.
A list of all parts in the ISO 9211 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

v
International Standard ISO 9211-3:2024(en)
Optics and photonics — Optical coatings —
Part 3:
Environmental durability
1 Scope
ISO 9211 (series) describes surface treatments of components and substrates excluding ophthalmic optics
(spectacles) by the application of optical coatings and gives a standard form for their specification. It
defines the general characteristics and the test and measurement methods whenever necessary, but it is not
intended to define the process method.
This document specifies general use and standard categories of use for optical coatings and identifies which
environmental tests are necessary to prove that the coatings meet the required specification. The mechanical
and chemical properties of coated optical elements, and more generally their environmental durability, can
be assessed by a variety of methods. The test methods are generally described in various parts of ISO 9022
and in ISO 9211-4. These test methods are selected to give meaningful results representative of actual
exposure of optical elements in their operating environment, alternatively to the minimum requirements as
described in ISO 9211-5 to ISO 9211-8, which are coating type related.
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 9022-1, Optics and photonics — Environmental test methods — Part 1: Definitions, extent of testing
ISO 9022-2, Optics and photonics — Environmental test methods — Part 2: Cold, heat and humidity
ISO 9022-4, Optics and photonics — Environmental test methods — Part 4: Salt mist
ISO 9022-6, Optics and photonics — Environmental test methods — Part 6: Dust
ISO 9022-9, Optics and photonics — Environmental test methods — Part 9: Solar radiation and weathering
ISO 9022-11, Optics and photonics — Environmental test methods — Part 11: Mould growth
ISO 9022-12, Optics and photonics — Environmental test methods — Part 12: Contamination
ISO 9022-14, Optics and photonics — Environmental test methods — Part 14: Dew, hoarfrost, ice
ISO 9211-4, Optics and optical instruments — Optical coatings — Part 4: Specific test methods: abrasion,
adhesion and resistance to water
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp

— IEC Electropedia: available at https:// www .electropedia .org/
4 General information for use
4.1 Environmental test code
The coating environmental durability tests should be listed according the environmental test code notation.
In the case that the ISO base number is the ISO 9022 series, the part of ISO 9022 shall not to be listed, as per
the notation in ISO 9022-1, as shown in Figure 1. Only the conditioning method and degree of severity shall
be listed following the ISO 9022 base number for the test code.
NOTE The test code notation from ISO 9022-1 is slightly different in that this description does not include the
statement “Environmental test”. The environmental test name should be included as a descriptor to the environmental
test code to avoid confusion, but is not directly a part of the environmental test code.
Figure 1 — Code for environmental tests
If the environmental durability test is one specified from ISO 9211-4, the ISO base number shall be listed as
9211-4, as shown in Figure 2. This notation still includes the conditioning method and degree of severity.
NOTE The test code notation from ISO 9211-4 is slightly different in that this description does not include the
statement “Coating environmental durability test”. The coating environmental durability test name should be included
as a descriptor to the environmental test code to avoid confusion, but is not directly a part of the environmental test
code.
Figure 2 — Code for coating environmental durability tests
4.2 Standard categories of use
4.2.1 General
Four standard categories of use and one non-standard category of use are defined. The four standard
categories of use represent different environmental conditions that a component may experience. Each
category requires either different environmental tests and/or different degrees of severity. These categories
are listed below in order of severity of requirement. These categories are a summary of use cases and are
not exhaustive of all instances.
A complete description of environmental durability tests, necessary for all standard categories of use, shall
be implemented as provided in Annex A.

4.2.2 Category A
This category refers to components in applications which would normally only apply when they are
to be mounted internally within sealed units. In this category, handling is in a protected and controlled
environment and should only take place with extreme care. Physical contact with the optically coated
surface is discouraged. See Table 1 for complete test sequence.
Table 1 — Default test sequence for Category of use A (one test sample is used)
Test code Test Description
Expose to a temperature of −25 °C ± 3 °C
1 ISO 9022-10-05 Cold x
for 16 h
Expose to an atmosphere of 55 °C ± 2 °C
2 ISO 9022-11-03 Dry heat x
(below 40 % relative humidity) for 16 h
4.2.3 Category B
This category refers to applications where components will be exposed only to a controlled environment.
Such applications may involve mild abrasion such as occurs with carefully controlled cleaning. See Table 2
for complete test sequence.
Table 2 — Default test sequence for Category of use B (two test samples are used)
Test code Test Description
1 ISO 9211-4-02-01 Adhesion: tape test Slow tape removal x x
Abrasion: cheesecloth/
2 ISO 9211-4-01-01 50 strokes cheesecloth x
eraser test
Expose to a temperature of −35 °C ± 3 °C
3 ISO 9022-10-07 Cold x
for 16 h
Expose to an atmosphere of 70 °C ± 2 °C
4 ISO 9022-11-05 Dry heat x
(below 40 % relative humidity) for 6 h
Expose to climatic conditions of 90 %
5 ISO 9022-12-06 Damp heat to 95 % relative humidity and 55 °C ± 2 °C x
for 6 h
−25 °C ± 3 °C to +55 °C ± 2 °C
Number of cycles: 5
Dwell time: wait until sample has reached
6 ISO 9022-14-02 Slow temperature change x
a temperature within at least 3 K of the test
chamber temperature but not less than 2,5 h
Test chamber temperature change rate: be-
tween 0,2 K/min and 2 K/min
Laboratory agent: Acetone
7 ISO 9022-87-01 5 min x
(CH COCH )
3 3
Laboratory agent: Ethanol
8 ISO 9022-87-01 5 min x
(C H OH)
2 5
9 ISO 9211-4-02-01 Adhesion: tape test Slow tape removal x x

Test step
Test step
Sample 1
Sample 1
Sample 2
4.2.4 Category C
This category refers to applications where components will be exposed to normal outdoor ambient
conditions and cleaning but without severe abrasion and scratching. See Table 3 for complete test sequence.
Table 3 — Default test sequence for Category of use C (three test samples are used)
Test code Test Description
1 ISO 9211-4-02-02 Adhesion: tape test Quick tape removal x x x
Abrasion: cheesecloth/
2 ISO 9211-4-01-02 100 strokes cheesecloth x
eraser test
Resistance to water: Immerse in distilled or deionized water
3 ISO 9211-4-04-01 x
exposure to water at a temperature of 23 °C ± 2 °C for 6 h
Resistance to water: Immerse in boiling distilled or deionized
4 ISO 9211-4-04-07 x
exposure to water water for 5 min
Expose to a temperature of
5 ISO 9022-10-07 Cold x
−35 °C ± 3 °C for 16 h
Expose to an atmosphere of 70 °C ± 2 °C
6 ISO 9022-11-05 Dry heat x
(below 40 % relative humidity) for 6 h
Expose to climatic conditions of 90 %
7 ISO 9022-12-07 Damp heat to 95 % relative humidity and 55 °C ± 2 °C x
for 16 h
−35 °C ± 3 °C to +63 °C ± 2 °C
Number of cycles: 5
Dwell time: wait until sample has reached
Slow temperature
a temperature within at least 3 K of the
8 ISO 9022-14-05 x
change
test chamber temperature but not less than
2,5 h
Test chamber temperature change rate:
between 0,2 K/min and
...