ASTM G90-23
(Practice)Standard Practice for Performing Accelerated Outdoor Weathering of Materials Using Concentrated Natural Sunlight
Standard Practice for Performing Accelerated Outdoor Weathering of Materials Using Concentrated Natural Sunlight
SIGNIFICANCE AND USE
4.1 Results obtained from this practice can be used to compare the relative durability of materials subjected to the specific test cycle used. No accelerated test can be specified as a perfect simulation of natural or field exposures. Results obtained from this practice can be considered as representative of natural weathering only when a sufficient magnitude of mathematical correlation exists between exposures.
4.2 The acceleration factor relating the rate of degradation in this accelerated exposure to the rate of degradation in a natural weathering exposure varies with the type and formulation of the material. Each material and formulation may respond differently to the increased level of irradiance and differences in temperature and humidity. Thus an acceleration factor determined for one material may not be applicable to other materials. For this reason, the use of a single acceleration factor is not recommended. Also, a different acceleration factor may be obtained by using different mirror types and configurations. Because of variability in test results for both accelerated and natural weathering exposures, results from a sufficient number of tests must be obtained to determine an acceleration factor for a material. Further, the acceleration factor is applicable to only one exposure location because results from natural weathering will vary due to seasonal or annual differences in climatic factors.
4.3 The relative durability of materials determined by this practice can be used to determine the relative durability of the materials exposed under natural weathering conditions provided the materials have similar acceleration factors. However, even if results from a specific accelerated test condition are found to be useful for comparing the durability of materials exposed in a particular exterior location, it cannot be assumed that they will be useful for determining the relative durability for a different location. The relative durability of materials in n...
SCOPE
1.1 Linear Fresnel reflector concentrators using the sun as source are utilized in the accelerated outdoor exposure testing of materials.
1.2 This practice covers a procedure for performing accelerated outdoor exposure testing of materials using a linear Fresnel reflector, accelerated outdoor weathering, test machine. The apparatus (see Fig. 1 and Fig. 2) and guidelines are described herein to minimize the variables encountered during outdoor accelerated exposure testing.
1.3 This practice does not specify the exposure conditions best suited for the materials to be tested but is limited to the method of obtaining, measuring, and controlling the procedures and certain conditions of the exposure. Sample preparation, test conditions, and evaluation of results are covered in existing methods or specifications for specific materials.
1.4 The linear Fresnel reflector accelerated outdoor exposure test apparatus described may be suitable for the determination of the relative durability of materials when these materials are exposed to concentrated sunlight, heat, and moisture.
1.5 This practice establishes uniform sample mounting and in-test maintenance procedures. Also included in the practice are standard provisions for maintenance of the machine and linear Fresnel reflector mirrors to ensure cleanliness and durability.
1.6 This practice shall apply to specimens whose size meets the dimensions of the target board as described in 8.2.
1.7 For test machines currently in use, this practice is not recommended for specimens exceeding 13 mm (1/2 in.) in thickness because of specimen cooling.
1.8 Values stated in SI units are to be regarded as the standard. The inch-pound units in parentheses are provided for information only.
1.9 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...
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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: G90 − 23
Standard Practice for
Performing Accelerated Outdoor Weathering of Materials
1
Using Concentrated Natural Sunlight
This standard is issued under the fixed designation G90; 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* 1.8 Values stated in SI units are to be regarded as the
standard. The inch-pound units in parentheses are provided for
1.1 Linear Fresnel reflector concentrators using the sun as
information only.
source are utilized in the accelerated outdoor exposure testing
1.9 This standard does not purport to address all of the
of materials.
safety concerns, if any, associated with its use. It is the
1.2 This practice covers a procedure for performing accel-
responsibility of the user of this standard to establish appro-
erated outdoor exposure testing of materials using a linear
priate safety, health, and environmental practices and deter-
Fresnel reflector, accelerated outdoor weathering, test machine.
mine the applicability of regulatory limitations prior to use.
The apparatus (see Fig. 1 and Fig. 2) and guidelines are
1.10 This international standard was developed in accor-
described herein to minimize the variables encountered during
dance with internationally recognized principles on standard-
outdoor accelerated exposure testing.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.3 This practice does not specify the exposure conditions
mendations issued by the World Trade Organization Technical
best suited for the materials to be tested but is limited to the
Barriers to Trade (TBT) Committee.
method of obtaining, measuring, and controlling the proce-
dures and certain conditions of the exposure. Sample
2. Referenced Documents
preparation, test conditions, and evaluation of results are
2
covered in existing methods or specifications for specific
2.1 ASTM Standards:
materials.
D859 Test Method for Silica in Water
D1014 Practice for Conducting Exterior Exposure Tests of
1.4 The linear Fresnel reflector accelerated outdoor expo-
Paints and Coatings on Metal Substrates
sure test apparatus described may be suitable for the determi-
D1435 Practice for Outdoor Weathering of Plastics
nation of the relative durability of materials when these
3
D1898 Practice for Sampling of Plastics (Withdrawn 1998)
materials are exposed to concentrated sunlight, heat, and
D4141 Practice for Conducting Black Box and Solar Con-
moisture.
centrating Exposures of Coatings
1.5 This practice establishes uniform sample mounting and
D4364 Practice for Performing Outdoor Accelerated Weath-
in-test maintenance procedures. Also included in the practice ering Tests of Plastics Using Concentrated Sunlight
are standard provisions for maintenance of the machine and
D4517 Test Method for Low-Level Total Silica in High-
linear Fresnel reflector mirrors to ensure cleanliness and Purity Water by Flameless Atomic Absorption Spectros-
durability.
copy
D5722 Practice for Performing Accelerated Outdoor Weath-
1.6 This practice shall apply to specimens whose size meets
ering of Factory-Coated Embossed Hardboard Using Con-
the dimensions of the target board as described in 8.2.
centrated Natural Sunlight and a Soak-Freeze-Thaw Pro-
1.7 For test machines currently in use, this practice is not
cedure
1
recommended for specimens exceeding 13 mm ( ⁄2 in.) in E816 Test Method for Calibration of Pyrheliometers by
thickness because of specimen cooling.
Comparison to Reference Pyrheliometers
1 2
This practice is under the jurisdiction of ASTM Committee G03 on Weathering For referenced ASTM standards, visit the ASTM website, www.astm.org, or
and Durabilityand is the direct responsibility of Subcommittee G03.02 on Natural contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
and Environmental Exposure Tests. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved July 1, 2023. Published August 2023. Originally the ASTM website.
3
approved in 1985. Last previous edition approved in 2017 as G90 – 17. DOI: The last approved version of this historical standard is referenced on
10.1520/G0090-23. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------
...
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: G90 − 17 G90 − 23
Standard Practice for
Performing Accelerated Outdoor Weathering of Materials
1
Using Concentrated Natural Sunlight
This standard is issued under the fixed designation G90; 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 Scope*
1.1 Fresnel-reflecting Linear Fresnel reflector concentrators using the sun as source are utilized in the accelerated outdoor
exposure testing of materials.
1.2 This practice covers a procedure for performing accelerated outdoor exposure testing of materials using a Fresnel-reflector
linear Fresnel reflector, accelerated outdoor weathering, test machine. The apparatus (see Fig. 1 and Fig. 2) and guidelines are
described herein to minimize the variables encountered during outdoor accelerated exposure testing.
1.3 This practice does not specify the exposure conditions best suited for the materials to be tested but is limited to the method
of obtaining, measuring, and controlling the procedures and certain conditions of the exposure. Sample preparation, test conditions,
and evaluation of results are covered in existing methods or specifications for specific materials.
1.4 The Fresnel-reflector linear Fresnel reflector accelerated outdoor exposure test machinesapparatus described may be suitable
for the determination of the relative durability of materials when these materials are exposed to concentrated sunlight, heat, and
moisture, provided the mechanisms of chemical or physical change, or both, which control the acceleration factors for the materials
do not differ significantly.moisture.
1.5 This practice establishes uniform sample mounting and in-test maintenance procedures. Also included in the practice are
standard provisions for maintenance of the machine and Fresnel-reflector linear Fresnel reflector mirrors to ensure cleanliness and
durability.
1.6 This practice shall apply to specimens whose size meets the dimensions of the target board as described in 8.2.
1
1.7 For test machines currently in use, this practice may not apply tois not recommended for specimens exceeding 13 mm ( ⁄2 in.)
in thickness because cooling may be questionable.of specimen cooling.
1.8 Values stated in SI units are to be regarded as the standard. The inch-pound units in parentheses are provided for information
only.
1.9 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
This practice is under the jurisdiction of ASTM Committee G03 on Weathering and Durabilityand is the direct responsibility of Subcommittee G03.02 on Natural and
Environmental Exposure Tests.
Current edition approved Dec. 1, 2017July 1, 2023. Published December 2017August 2023. Originally approved in 1985. Last previous edition approved in 20102017 as
G90 – 10.G90 – 17. DOI: 10.1520/G0090-17.10.1520/G0090-23.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
G90 − 23
FIG. 1 Schematic of Fresnel-Reflecting Linear Fresnel Reflector Concentrator Accelerated Weathering Machine Single Axis Tracking
1.10 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:
D859 Test Method for Silica in Water
D1014 Practice for Conducting Exterior Exposure Tests of Paints and Coatings on Metal Substrates
D1435 Practice for Outdoor Weathering of Plastics
3
D1898 Practice for Sampling of Plastics (Withdrawn 1998)
D4141 Practice for Conducting Black Box and Solar Concentrating Exposures of Coatings
D4364 Practice for Performing Outdoor Accelerated Weathering Tests of Plastics Using Concentrated Sunlight
D4517 Test Method for Low-Level Total Silica in High-Purity Water by Flameless Atomic Absorption Spectroscopy
D5722 Pr
...
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