ASTM F520-21

Standard Test Method for Environmental Resistance of Aerospace Transparencies to Artificially Induced Exposures

SIGNIFICANCE AND USE
4.1 This test method, when applied to aerospace transparencies of either monolithic glass/plastic or laminated combinations, is a measure of the ability of the transparency to withstand the effects of artificially induced environments. The test applies to configurations employing electrically conductive coatings, and also to uncoated materials.  
4.2 The resistance of the transparent enclosure to environmental effects may vary appreciably depending on the size, geometry, material of construction, coating integrity, coating density, and other factors.
SCOPE
1.1 This test method covers determination of the effects of exposure to thermal shock, condensing humidity, and simulated weather on aerospace transparent enclosures.  
1.2 This test method is not recommended for quality control, nor is it intended to provide a correlation to actual service life.  
1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3.1 Exceptions—Certain inch-pound units are furnished in parentheses (not mandatory) and certain temperatures in Fahrenheit associated with other standards are also furnished.  
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Apr-2021
• ICS: 49.045 - Structure and structure elements
• Technical Committee: F07 - Aerospace and Aircraft
• Drafting Committee: F07.08 - Transparent Enclosures and Materials

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F520 −21
Standard Test Method for
Environmental Resistance of Aerospace Transparencies to
1
Artificially Induced Exposures
ThisstandardisissuedunderthefixeddesignationF520;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope F521Test Methods for Bond Integrity of Transparent Lami-
nates
1.1 This test method covers determination of the effects of
G53Practice for Operating Light-and Water-Exposure Ap-
exposure to thermal shock, condensing humidity, and simu-
paratus (Fluorescent UV-Condensation Type) for Expo-
lated weather on aerospace transparent enclosures.
3
sure of Nonmetallic Materials (Withdrawn 2000)
1.2 This test method is not recommended for quality
G154Practice for Operating Fluorescent Ultraviolet (UV)
control, nor is it intended to provide a correlation to actual
Lamp Apparatus for Exposure of Nonmetallic Materials
service life.
3. Summary of Test Method
1.3 Units—The values stated in SI units are to be regarded
asstandard.Nootherunitsofmeasurementareincludedinthis 3.1 Two types of test specimens, duplicating the aerospace
standard.
transparent enclosure design, are subjected to thermal shock,
1.3.1 Exceptions—Certaininch-poundunitsarefurnishedin condensing humidity, and artificial weathering. Edge sealing
parentheses (not mandatory) and certain temperatures in Fahr-
shall be used if representative of the design.
enheit associated with other standards are also furnished. 3.1.1 TypeAspecimensshallbeusedtodeterminetheeffect
of environmental exposure on electrical and optical properties.
1.4 This standard does not purport to address all of the
3.1.2 TypeBspecimensshallbeusedtodeterminetheeffect
safety concerns, if any, associated with its use. It is the
of environmental exposure on bond integrity.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4. Significance and Use
mine the applicability of regulatory limitations prior to use.
4.1 This test method, when applied to aerospace transpar-
1.5 This international standard was developed in accor-
encies of either monolithic glass/plastic or laminated
dance with internationally recognized principles on standard-
combinations,isameasureoftheabilityofthetransparencyto
ization established in the Decision on Principles for the
withstand the effects of artificially induced environments. The
Development of International Standards, Guides and Recom-
testappliestoconfigurationsemployingelectricallyconductive
mendations issued by the World Trade Organization Technical
coatings, and also to uncoated materials.
Barriers to Trade (TBT) Committee.
4.2 The resistance of the transparent enclosure to environ-
2. Referenced Documents
mental effects may vary appreciably depending on the size,
2
geometry, material of construction, coating integrity, coating
2.1 ASTM Standards:
density, and other factors.
D1003Test Method for Haze and Luminous Transmittance
of Transparent Plastics
5. Test Specimens
F319Practice for Polarized Light Detection of Flaws in
Aerospace Transparency Heating Elements 5.1 Each Type A specimen to be evaluated for external
coating durability shall be a 250 by 250mm (9.8 by 9.8in.)
cross section of the design and shall contain, as applicable,
surface coatings of operational, electrically conducting coating
1
This test method is under the jurisdiction of ASTM Committee F07 on
Aerospace andAircraft and is the direct responsibility of Subcommittee F07.08 on systems complete with bus bars, braids, and temperature
Transparent Enclosures and Materials.
sensors.
Current edition approved May 1, 2021. Published June 2021. Originally
5.1.1 Type A test specimens shall have a fully operational
approved in 1977. Last previous edition approved in 2016 as F520–16. DOI:
coating system, when applicable, with an average resistivity
10.1520/F0520-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
F520 − 21
consistent with the average resistivity of the representative 7.2 Optical Tests—Measure each Typ
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F520 − 16 F520 − 21
Standard Test Method for
Environmental Resistance of Aerospace Transparencies to
1
Artificially Induced Exposures
This standard is issued under the fixed designation F520; the number immediately following the designation indicates the year of original
adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers determination of the effects of exposure to thermal shock, condensing humidity, and simulated weather
on aerospace transparent enclosures.
1.2 This test method is not recommended for quality control, nor is it intended to provide a correlation to actual service life.
1.3 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this
standard.
1.3.1 Exceptions—Certain inch-pound units are furnished in parentheses (not mandatory) and certain temperatures in Fahrenheit
associated with other standards are also furnished.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
D1003 Test Method for Haze and Luminous Transmittance of Transparent Plastics
F319 Practice for Polarized Light Detection of Flaws in Aerospace Transparency Heating Elements
F521 Test Methods for Bond Integrity of Transparent Laminates
G53 Practice for Operating Light-and Water-Exposure Apparatus (Fluorescent UV-Condensation Type) for Exposure of
3
Nonmetallic Materials (Withdrawn 2000)
G154 Practice for Operating Fluorescent Ultraviolet (UV) Lamp Apparatus for Exposure of Nonmetallic Materials
1
This test method is under the jurisdiction of ASTM Committee F07 on Aerospace and Aircraft and is the direct responsibility of Subcommittee F07.08 on Transparent
Enclosures and Materials.
Current edition approved April 1, 2016May 1, 2021. Published May 2016June 2021. Originally approved in 1977. Last previous edition approved in 20102016 as
F520 – 10.F520 – 16. DOI: 10.1520/F0520-16.10.1520/F0520-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
F520 − 21
3. Summary of Test Method
3.1 Two types of test specimens, duplicating the aerospace transparent enclosure design, are subjected to thermal shock,
condensing humidity, and artificial weathering. Edge sealing shall be used if representative of the design.
3.1.1 Type A specimens shall be used to determine the effect of environmental exposure on electrical and optical properties.
3.1.2 Type B specimens shall be used to determine the effect of environmental exposure on bond integrity.
4. Significance and Use
4.1 This test method, when applied to aerospace transparencies of either monolithic glass/plastic or laminated combinations, is a
measure of the ability of the transparency to withstand the effects of artificially induced environments. The test applies to on
configurations employing electrically conductive coatings, and also to uncoated materials.
4.2 The resistance of the transparent enclosure to environmental effects may vary appreciably depending on the size, geometry,
material of construction, coating integrity, coating density, and other factors.
5. Test Specimens
5.1 Each Type A specimen to be evaluated for external coating durability shall be a 250 by 250-mm250 mm (9.8 by 9.8-in.)9.8 in.)
cross section of the design and shall contain, as applicable, surface coatings of operational, electrically conducti
...