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ASTM G7/G7M-11

(Practice)

Standard Practice for Atmospheric Environmental Exposure Testing of Nonmetallic Materials

Standard Practice for Atmospheric Environmental Exposure Testing of Nonmetallic Materials

SIGNIFICANCE AND USE
The relative durability of materials in natural exposures can be very different depending on the location of the exposure because of differences in ultraviolet (UV) radiation, time of wetness, temperature, pollutants, and other factors. Therefore, it cannot be assumed that results from one exposure in a single location will be useful for determining relative durability in a different location. Exposures in several locations with different climates which represent a broad range of anticipated service conditions are recommended.
Because of year-to-year climatological variations, results from a single exposure test cannot be used to predict the absolute rate at which a material degrades. Several years of repeat exposures are needed to get an “average” test result for a given location.
Solar ultraviolet radiation varies considerably as a function of time of year. This can cause large differences in the apparent rate of degradation in many polymers. Comparing results for materials exposed for short periods (less than one year) is not recommended unless materials are exposed at the same time in the same location.
Defining exposure periods in terms of total solar or solar-ultraviolet radiant energy can reduce variability in results from separate exposures. Solar ultraviolet measurements are typically made using instruments which record broadband UV (for example, 295 to 385 nm) or narrow band UV, as described in 7.2.4 and 7.2.5. An inherent limitation in solar-radiation measurements is that they do not reflect the effects of temperature and moisture, which may also influence the rate or type of degradation.
The design of the exposure rack, the location of the specimen on the exposure rack, and the type or color of adjacent specimens can affect specimen temperature and time of wetness. In order to minimize variability caused by these factors, it is recommended that test specimens, control specimens, and any applicable weathering reference material be placed on a sing...
SCOPE
1.1 This practice covers procedures to be followed for direct exposure of nonmetallic materials to the environment. When originators of a weathering test have the actual exposure conducted by a separate agency, the specific conditions for the exposure of test and control specimens must be clearly defined and mutually agreed upon between all parties.
1.2 For exposures behind glass, refer to Practice G24.
1.3 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
1.4 This practice is technically equivalent to the parts of ISO 877 that describe direct exposures of specimens to the environment.
1.5 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

Status
Historical
Publication Date
31-May-2011
ICS
19.040 - Environmental testing
Technical Committee
G03 - Weathering and Durability
Drafting Committee
G03.02 - Natural and Environmental Exposure Tests
Current Stage
Ref Project

Relations

Replaces
ASTM G7-05 - Standard Practice for Atmospheric Environmental Exposure Testing of Nonmetallic Materials
Effective Date
01-Jun-2011
Referred By
ASTM E782-95(2022) - Standard Practice for Exposure of Cover Materials for Solar Collectors to Natural Weathering Under Conditions Simulating Operational Mode
Effective Date
01-Jun-2011
Referred By
ASTM D4364-13(2022)e1 - Standard Practice for Performing Outdoor Accelerated Weathering Tests of Plastics Using Concentrated Sunlight
Effective Date
01-Jun-2011
Referred By
ASTM E881-92(2022) - Standard Practice for Exposure of Solar Collector Cover Materials to Natural Weathering Under Conditions Simulating Stagnation Mode
Effective Date
01-Jun-2011
Referred By
ASTM D5970/D5970M-16(2021) - Standard Test Method for Deterioration of Geotextiles from Outdoor Exposure
Effective Date
01-Jun-2011
Referred By
ASTM D8514/D8514M-23 - Standard Specification for Flexible, Retroreflective Sheeting for Use in High Visibility Vehicle Markings
Effective Date
01-Jun-2011
Referred By
ASTM D4956-19 - Standard Specification for Retroreflective Sheeting for Traffic Control
Effective Date
01-Jun-2011
Referred By
ASTM D5272-08(2021) - Standard Practice for Outdoor Exposure Testing of Photodegradable Plastics
Effective Date
01-Jun-2011

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ASTM G7/G7M-11 - Standard Practice for Atmospheric Environmental Exposure Testing of Nonmetallic MaterialsASTM G7/G7M-11 - Standard Practice for Atmospheric Environmental Exposure Testing of Nonmetallic Materials
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ASTM G7/G7M-11 - Standard Practice for Atmospheric Environmental Exposure Testing of Nonmetallic Materials
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Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: G7/G7M − 11
StandardPractice for
Atmospheric Environmental Exposure Testing of
1
Nonmetallic Materials
This standard is issued under the fixed designation G7/G7M; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope* E941 Test Method for Calibration of Reference Pyranom-
etersWithAxisTiltedbytheShadingMethod(Withdrawn
1.1 Thispracticecoversprocedurestobefollowedfordirect
3
2005)
exposure of nonmetallic materials to the environment. When
G24 Practice for Conducting Exposures to Daylight Filtered
originators of a weathering test have the actual exposure
Through Glass
conducted by a separate agency, the specific conditions for the
G113 Terminology Relating to Natural andArtificial Weath-
exposure of test and control specimens must be clearly defined
ering Tests of Nonmetallic Materials
and mutually agreed upon between all parties.
G130 Test Method for Calibration of Narrow- and Broad-
1.2 For exposures behind glass, refer to Practice G24.
Band Ultraviolet Radiometers Using a Spectroradiometer
1.3 The values stated in SI units are to be regarded as the 2.2 ISO Standards:
standard. The inch-pound units given in parentheses are for
ISO 877 Plastics—Methods of Exposure to Direct Weath-
information only. ering;toWeatheringUsingGlass-FilteredDaylight,andto
Intensified Weathering by Daylight Using Fresnel Mir-
1.4 This practice is technically equivalent to the parts of
4
rors
ISO 877 that describe direct exposures of specimens to the
ISO 9370 Plastics—Instrumental Determination of Radiant
environment.
Exposure in Weathering Tests—General Guidance and
1.5 This standard does not purport to address all of the 4
Basic Test Method
safety concerns, if any, associated with its use. It is the
2.3 ASTM Adjuncts:
responsibility of the user of this standard to establish appro-
5
A Test Rack
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
3. Terminology
3.1 Definitions—The definitions given in Terminology E41
2. Referenced Documents
and Terminology G113 are applicable to this practice.
2
2.1 ASTM Standards:
E41 Terminology Relating To Conditioning
4. Significance and Use
E824 Test Method for Transfer of Calibration From Refer-
4.1 The relative durability of materials in natural exposures
ence to Field Radiometers
can be very different depending on the location of the exposure
E913 Method for Calibration of Reference Pyranometers
because of differences in ultraviolet (UV) radiation, time of
With Axis Vertical by the Shading Method (Withdrawn
wetness, temperature, pollutants, and other factors. Therefore,
3
2005)
it cannot be assumed that results from one exposure in a single
location will be useful for determining relative durability in a
different location. Exposures in several locations with different
1
This practice is under the jurisdiction ofASTM Committee G03 on Weathering
climates which represent a broad range of anticipated service
and Durabilityand is the direct responsibility of Subcommittee G03.02 on Natural
conditions are recommended.
and Environmental Exposure Tests.
CurrenteditionapprovedJune1,2011.PublishedJuly2011.Originallyapproved
4.2 Because of year-to-year climatological variations, re-
in 1969. Last previous edition approved in 2005 as G7 – 05. DOI: 10.1520/G0007
sults from a single exposure test cannot be used to predict the
_G0007M-11.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
4
Standards volume information, refer to the standard’s Document Summary page on Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
3 5
The last approved version of this historical standard is referenced on Detailed drawings for an acceptable test rack may be obtained from ASTM
www.astm.org. International. Request ADJG0007.
*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 ----------------------
G7/G7M − 11
absolute rate at which a material degrades. Several years of G113, and be of similar composition and construction com-
repeat exposures are needed to get an “average” test result for pared to test specimens. It is preferable to use two control
a given location. materials, one with relatively good durability a
...

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ASTM G90-23(Practice)
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...
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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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ASTM G154-23(Practice)
Standard Practice for Operating Fluorescent Ultraviolet (UV) Lamp Apparatus for Exposure of Materials

SIGNIFICANCE AND USE
5.1 The use of this apparatus is intended to induce property changes consistent with the end use conditions, including the effects of the UV portion of sunlight, moisture, and heat. Typically, these exposures would include moisture in the form of condensing humidity. Exposures are not intended to simulate the deterioration caused by localized weather phenomena, such as atmospheric pollution, biological attack, and saltwater exposure. Alternatively, the exposure may simulate the effects of sunlight through window glass. (Warning—Refer to Practice G151 for full cautionary guidance applicable to all laboratory weathering devices.)  
5.2 This practice provides general procedures for operating fluorescent UV lamp weathering devices that allow for a wide range of exposure conditions. Therefore, no reference shall be made to results from the use of this practice unless accompanied by a report detailing the specific operating conditions in conformance with Section 10.  
5.2.1 It is recommended that a similar material of known performance (a control) be exposed simultaneously with the test specimen to provide a standard for comparative purposes. Generally, two controls are recommended: one known to have poor durability and one known to have good durability. It is recommended that at least three replicates of each material evaluated be exposed in each test to allow for statistical evaluation of results.  
5.2.2 Comparison of results obtained from specimens exposed in the same model of apparatus should not be made unless reproducibility has been established among devices for the material to be tested.  
5.2.3 Comparison of results obtained from specimens exposed in different models of apparatus should not be made unless correlation has been established among devices for the material to be tested (see Guide D6631 for guidance).
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1.1 This practice is limited to the basic principles for operating a fluorescent UV lamp and water apparatus; on its own, it does not deliver a specific result.  
1.2 It is intended to be used in conjunction with a practice or method that defines specific exposure conditions for an application along with a means to evaluate changes in material properties. This practice is intended to reproduce the weathering effects that occur when materials are exposed to sunlight (either direct or through window glass) and moisture as rain or dew in actual usage. This practice is limited to the procedures for obtaining, measuring, and controlling conditions of exposure.
Note 1: Practice G151 describes general procedures to be used when exposing nonmetallic materials in accelerated test devices that use laboratory light sources.
Note 2: A number of exposure procedures are listed in an appendix; however, this practice does not specify the exposure conditions best suited for the material to be tested.  
1.3 Test specimens are exposed to fluorescent UV light under controlled environmental conditions. Different types of fluorescent UV lamp sources are described.
Note 3: In this standard, the terms UV light and UV radiation are used interchangeably.  
1.4 Specimen preparation and evaluation of the results are covered in ASTM methods or specifications for specific materials. General guidance is given in Practice G151 and ISO 4892-1.
Note 4: General information about methods for determining the change in properties after exposure and reporting these results is described in ISO 4582 and Practice D5870.  
1.5 This practice is not intended for corrosion testing of bare metals.  
1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.7 This standard is technically similar to ISO 4892-3 and ISO 16474-3.  
1.8 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...

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ASTM G7/G7M-21(Practice)
Standard Practice for Natural Weathering of Materials

SIGNIFICANCE AND USE
4.1 The relative durability of materials in natural exposures can be very different depending on the location of the exposure because of differences in ultraviolet (UV) radiation, relative humidity, time of wetness, temperature, wet-dry cycling, freeze-thaw cycling, pollutants, and other factors. Therefore, it cannot be assumed that results from one exposure in a single location will be useful for determining relative durability in a different location. Exposures in several locations with different climates which represent a broad range of anticipated service conditions are recommended.  
4.2 Because of year-to-year climatological variations, results from a single exposure test cannot be used to predict the absolute rate at which a material degrades. Several exposures, repeated over several years are needed to get a representative test result for a given location.  
4.3 Solar UV radiation varies considerably as a function of time of year. This can cause large differences in the apparent rate of degradation in many materials. Comparing results for materials exposed for short periods (less than one year) is not recommended unless materials are exposed at the same time in the same location.  
4.4 The duration of natural weathering tests is often based on time (24 months for example). The variability between different exposures can be reduced by using a duration based on total solar or solar UV radiant exposure. Solar UV measurements are typically made using instruments which record broadband UV (for example, 295 to 385 nm), as described in 7.2.4. An inherent limitation in timing a weathering test based solely on solar-radiation measurements is that temperature and moisture may also influence the rate or type of degradation.  
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1.1 This practice covers procedures to be followed for direct exposure of materials to the environment. Typically, this testing is performed on exposure racks tilted at a commonly-used tilt angle from the horizontal (such as 5 or 45 degrees) and facing the equator. Other exposure orientations can be used.  
1.2 This practice is not intended for the corrosion testing of bare metals, or for testing behind glass.  
1.2.1 For corrosion testing, refer to Practice G50  
1.2.2 For exposures behind glass, refer to Practice G24  
1.3 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.4 This practice is technically equivalent to the parts of ISO 877-1 and -2 that describe direct exposures of specimens to the environment.  
1.5 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.  
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SIGNIFICANCE AND USE
5.1 The apparatus exposes specimens to light, heat, and optionally moisture, often to attempt to replicate specimen property changes observed in outdoor and indoor end-use environments. Exposures are not intended to simulate the deterioration caused by localized weather phenomena, such as atmospheric pollution, biological attack, and saltwater exposure.  
5.2 This practice allows a wide range of exposure conditions that may produce significantly different results. Therefore, no reference shall be made to results from its use unless accompanied by a report in conformance with Section 10 detailing the specific operating conditions.  
5.2.1 A control (a similar material of known performance) should be exposed simultaneously with the test specimen to provide a reference for comparative purposes. It is best practice to use two different control materials: one known to have relatively poor durability and one known to have relatively good durability. At least three replicates of each test specimen and control material should be exposed concurrently to permit statistical evaluation of results.  
5.3 Comparison of results obtained from specimens exposed in different apparatus (even if the apparatus is the same model) using the identical setpoints and operational controls should not be made unless reproducibility has been established between apparatus for the material to be tested.  
5.4 Refer to Practice G151 for cautionary guidance applicable to all laboratory weathering apparatus.  
5.5 It is recommended that users follow good laboratory practices in order to reduce variability in exposures (1).8
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1.1 This practice is limited to the basic principles and procedures for operating a xenon arc lamp and water apparatus; on its own, it does not deliver a specific result.  
1.2 It is intended to be used in conjunction with a practice or method that defines specific exposure conditions for an application along with a means to evaluate changes in material properties. This practice is intended to reproduce the weathering effects that occur when materials are exposed to sunlight (either direct or through window glass) and moisture as humidity, rain, or dew in actual use. This practice is limited to the procedures for obtaining, measuring, and controlling conditions of exposure.
Note 1: A number of exposure procedures are listed in an appendix; however, this practice does not specify the exposure conditions best suited for the material to be tested.
Note 2: Practice G151 describes general procedures and performance requirements to be used when exposing materials in an apparatus that uses laboratory light sources.  
1.3 Test specimens are exposed to light from an optically-filtered xenon arc lamp under controlled environmental conditions. Different types of optical filters in combination with xenon arc light sources are described.  
1.4 Specimen preparation and evaluation of the results are covered in ASTM methods or specifications for specific materials. General guidance is given in Practice G151.
Note 3: General information about methods for determining the change in properties after exposure and reporting these results is described in Practice D5870.  
1.5 This practice is not intended for corrosion testing of bare metals.  
1.6 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.7 This practice is technically similar to the following ISO documents: ISO 4892-2, ISO 16474-2, ISO 105-B02, ISO 105-B04, ISO 105-B05, ISO 105-B06, and ISO 105-B10.  
1.8 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.  
1.8.1 Should any ozone be generated from the operation of the la...

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ASTM G169-01(2021)(Guide)
Standard Guide for Application of Basic Statistical Methods to Weathering Tests

SIGNIFICANCE AND USE
4.1 The correct use of statistics as part of a weathering program can greatly increase the usefulness of results. A basic understanding of statistics is required for the study of weathering performance data. Proper experimental design and statistical analysis strongly enhances decision-making ability. In weathering, there are many uncertainties brought about by exposure variability, method precision and bias, measurement error, and material variability. Statistical analysis is used to help decide which products are better, which test methods are most appropriate to gauge end use performance, and how reliable the results are.  
4.2 Results from weathering exposures can show differences between products or between repeated testing. These results may show differences which are not statistically significant. The correct use of statistics on weathering data can increase the probability that valid conclusions are derived.
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1.1 This guide covers elementary statistical methods for the analysis of data common to weathering experiments. The methods are for decision making, in which the experiments are designed to test a hypothesis on a single response variable. The methods work for either natural or laboratory weathering.  
1.2 Only basic statistical methods are presented. There are many additional methods which may or may not be applicable to weathering tests that are not covered in this guide.  
1.3 This guide is not intended to be a manual on statistics, and therefore some general knowledge of basic and intermediate statistics is necessary. The text books referenced at the end of this guide are useful for basic training.  
1.4 This guide does not provide a rigorous treatment of the material. It is intended to be a reference tool for the application of practical statistical methods to real-world problems that arise in the field of durability and weathering. The focus is on the interpretation of results. Many books have been written on introductory statistical concepts and statistical formulas and tables. The reader is referred to these for more detailed information. Examples of the various methods are included. The examples show typical weathering data for illustrative purposes, and are not intended to be representative of specific materials or exposures.  
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.

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ASTM G153-13(2021)(Practice)
Standard Practice for Operating Enclosed Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials

SIGNIFICANCE AND USE
5.1 The use of this apparatus is intended to induce property changes associated with the end use conditions, including the effects of sunlight, moisture, and heat. These exposures may include a means to introduce moisture to the test specimen. Exposures are not intended to simulate the deterioration caused by localized weather phenomena, such as atmospheric pollution, biological attack, and saltwater exposure. Alternatively, the exposure may simulate the effects of sunlight through window glass. Typically, these exposures would include moisture in the form of humidity.
Note 2: Caution: Refer to Practice G151 for full cautionary guidance applicable to all laboratory weathering devices.  
5.2 Variation in results may be expected when operating conditions are varied within the accepted limits of this practice. Therefore, no reference shall be made to results from the use of this practice unless accompanied by a report detailing the specific operating conditions in conformance with Section 10.  
5.2.1 It is recommended that a similar material of known performance, a control, be exposed simultaneously with the test specimen to provide a standard for comparative purposes. It is best practice to use control materials known to have relatively poor and good durability. It is recommended that at least three replicates of each material evaluated be exposed in each test to allow for statistical evaluation of results.
SCOPE
1.1 This practice covers the basic principles and operating procedures for using enclosed carbon-arc light and water apparatus intended to reproduce the weathering effects that occur when materials are exposed to sunlight (either direct or through window glass) and moisture as rain or dew in actual use. This practice is limited to the procedures for obtaining, measuring, and controlling conditions of exposure. A number of exposure procedures are listed in an appendix; however, this practice does not specify the exposure conditions best suited for the material to be tested.
Note 1: Practice G151 describes performance criteria for all exposure devices that use laboratory light sources. This practice replaces Practice G23, which describes very specific designs for devices used for carbon-arc exposures. The apparatus described in Practice G23 is covered by this practice.  
1.2 Test specimens are exposed to enclosed carbon arc light under controlled environmental conditions.  
1.3 Specimen preparation and evaluation of the results are covered in various methods or specifications for specific materials. General guidance is given in Practice G151 and ISO 4892-1. More specific information about methods for determining the change in properties after exposure and reporting these results is described in ISO 4582.  
1.4 The values stated in SI units are to be regarded as the standard.  
1.5 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.  
1.5.1 Should any ozone be generated from the operation of the light source, it shall be carried away from the test specimens and operating personnel by an exhaust system.  
1.6 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.

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ASTM G152-13(2021)(Practice)
Standard Practice for Operating Open Flame Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials

SIGNIFICANCE AND USE
5.1 The use of this apparatus is intended to induce property changes associated with the end use conditions, including the effects of sunlight, moisture, and heat. These exposures may include a means to introduce moisture to the test specimen. Exposures are not intended to simulate the deterioration caused by localized weather phenomena, such as atmospheric pollution, biological attack, and saltwater exposure. Alternatively, the exposure may simulate the effects of sunlight through window glass. Typically, these exposures would include moisture in the form of humidity.
Note 2: Caution: Refer to Practice G151 for full cautionary guidance applicable to all laboratory weathering devices.  
5.2 Variation in results may be expected when operating conditions are varied within the accepted limits of this practice. No reference, therefore, shall be made to results from the use of this practice unless accompanied by a report detailing the specific operating conditions in conformance with Section 10.  
5.2.1 It is recommended that a similar material of known performance, a control, be exposed simultaneously with the test specimen to provide a standard for comparative purposes. It is best practice to use control materials known to have relatively poor and good durability. It is recommended that at least three replicates of each material evaluated be exposed in each test to allow for statistical evaluation of results.
SCOPE
1.1 This practice covers the basic principles and operating procedures for using open flame carbon-arc light and water apparatus intended to reproduce the weathering effects that occur when materials are exposed to sunlight (either direct or through window glass) and moisture as rain or dew in actual use. This practice is limited to the procedures for obtaining, measuring, and controlling conditions of exposure. A number of exposure procedures are listed in an appendix; however, this practice does not specify the exposure conditions best suited for the material to be tested.
Note 1: Practice G151 describes performance criteria for all exposure devices that use laboratory light sources. This practice replaces Practice G23, which describes very specific designs for devices used for carbon-arc exposures. The apparatus described in Practice G23 is covered by this practice.  
1.2 Test specimens are exposed to filtered open flame carbon arc light under controlled environmental conditions. Different filters are described.  
1.3 Specimen preparation and evaluation of the results are covered in methods or specifications for specific materials. General guidance is given in Practice G151 and ISO 4892-1. More specific information about methods for determining the change in properties after exposure and reporting these results is described in Practice D5870.  
1.4 The values stated in SI units are to be regarded as the standard.  
1.5 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.  
1.5.1 Should any ozone be generated from the operation of the light source, it shall be carried away from the test specimens and operating personnel by an exhaust system.  
1.6 This practice is technically similar to ISO 4892-4.  
1.7 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.

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ASTM G160-12(2019)(Practice)
Standard Practice for Evaluating Microbial Susceptibility of Nonmetallic Materials By Laboratory Soil Burial

SIGNIFICANCE AND USE
3.1 These results may be used to compare the susceptibility of materials when exposed to this test procedure.  
3.2 Microbiological susceptibility may be reflected by a number of changes including staining, weight loss, or reduction in tensile or flexural strength.  
3.3 This practice may be considered an inoculation with a mixed culture of fungi and bacteria.
SCOPE
1.1 This practice is limited to the method of conducting an evaluation of a nonmetallic material's microbiological susceptibility when in contact with the natural environment of the soil under use conditions. This practice is intended for use on solid material test specimens that are no larger than approximately 2 cm (0.79 in.) thick and 100 cm 2  (15.5 in.2) or on film forming materials such as coatings which may be tested in the form of films at least 50 by 50 mm (2 by 2 in.) in size. This practice may be applied to articles that do not spend the majority of their service life in soil.  
1.2 A wide variety of properties may be affected by microbial attack depending on material or item characteristics. Standard methods (where available) should be used for each different property to be evaluated. This practice does not attempt to enumerate all of the possible properties of interest nor specify the most appropriate test for those properties. Test methods must, however, be appropriate to the material being tested.  
1.3 Materials intended for use in soil burial applications are often subjected to periods of exposure to solar radiation and other elements of weather for some time before they are buried. Because these exposures may alter the ability of a material to resist the effects of soil-borne microorganisms, it is recommended that this practice be combined with appropriate environmental exposures (for example, solar simulating weathering devices, the hydrolytic effects of extended aqueous contact, or extraneous nutrients) or fabrication into articles (for example, adhesive bonding of seams) which may promote microbiological susceptibility during the service life of the material.  
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information purposes only.  
1.5 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.  
1.6 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.

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ASTM
ASTM G151-19(Practice)
Standard Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources

SIGNIFICANCE AND USE
4.1 Significance:  
4.1.1 When conducting exposures in devices that use laboratory light sources, it is important to consider how well the accelerated test conditions will reproduce property changes and failure modes associated with end-use environments for the materials being tested. In addition, it is essential to consider the effects of variability in both the accelerated test and outdoor exposures when setting up exposure experiments and when interpreting the results from accelerated exposure tests.  
4.1.2 No laboratory exposure test can be specified as a total simulation of actual use conditions in outdoor environments. Results obtained from these laboratory accelerated exposures can be considered as representative of actual use exposures only when the degree of rank correlation has been established for the specific materials being tested and when the type of degradation is the same. The relative durability of materials in actual use conditions can be very different in different locations because of differences in UV radiation, time of wetness, relative humidity, temperature, pollutants, and other factors. Therefore, even if results from a specific exposure test conducted according to this practice are found to be useful for comparing the relative durability of materials exposed in a particular exterior environment, it cannot be assumed that they will be useful for determining relative durability of the same materials for a different environment.  
4.1.3 Even though it is very tempting, calculation of an acceleration factor relating  x h or megajoules of radiant exposure in a laboratory accelerated test to y months or years of exterior exposure is not recommended. These acceleration factors are not valid for several reasons.  
4.1.3.1 Acceleration factors are material dependent and can be significantly different for each material and for different formulations of the same material.
4.1.3.2 Variability in the rate of degradation in both actual use and la...
SCOPE
1.1 This practice covers general procedures to be used when exposing nonmetallic materials in accelerated test devices that use laboratory light sources. Detailed information regarding procedures to be used for specific devices are found in standards describing the particular device being used. For example, detailed information covering exposures in devices that use open flame carbon arc, enclosed carbon arc, xenon arc, and fluorescent UV light source are found in Practices G152, G153, G154, and G155 respectively.
Note 1: Carbon-arc, xenon arc, and fluorescent UV exposures were also described in Practices G23, G26, and G53 which referred to very specific equipment designs. Practices G152, G153, and G154, and G155 are performance based standards that replace Practices G23, G26, and G53.  
1.2 This practice also describes general performance requirements for devices used for exposing nonmetallic materials to laboratory light sources. This information is intended primarily for producers of laboratory accelerated exposure devices.  
1.3 This practice provides information on the use and interpretation of data from accelerated exposure tests. Specific information about methods for determining the property of a nonmetallic material before and after exposure are found in standards describing the method used to measure each property. Information regarding the reporting of results from exposure testing of plastic materials is described in Practice D5870.
Note 2: Guide G141 provides information for addressing variability in exposure testing of nonmetallic materials. Guide G169 provides information for application of statistics to exposure test results.
Note 3: This standard is technically equivalent to ISO 4892, Part 1.  
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, an...

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ASTM
ASTM G156-17(Practice)
Standard Practice for Selecting and Characterizing Weathering Reference Materials

SIGNIFICANCE AND USE
4.1 Weathering reference materials are used in laboratory accelerated exposure tests to verify consistency of tests run within the same instrument at different times (repeatability) or in different instruments or different laboratories (reproducibility), using the same exposure conditions, or both. Specifications defining consistency of exposure conditions are based on the property change of a reference material after a defined period of time. Some weathering reference materials are used to define periods of exposure. Specifications recommending the use of these materials require the material to be exposed until a defined change in the weathering reference material is achieved. Specifications are usually based on results for a single lot of the weathering reference material. When a new lot of the reference material is introduced, round-robin studies are necessary to compare the new and old lots and to establish appropriate limits for expected performance of the new lot.
Note 2: An example of the use of a clear polystyrene reference standard for this purpose is given in SAE J2412 and SAE J2527.
Note 3: Some weathering reference materials (for example blue wools) are also used to define periods of exposure. Although not specifically covered by this standard, the procedures described for characterizing a reference material used to monitor consistency of exposures are also generally applicable to characterizing reference materials used to define periods of exposure.  
4.2 It is important to test the consistency of exposure in the laboratory accelerated device with a weathering reference material that responds to the test conditions similar to the way the test materials respond. Therefore, the weathering reference material should be sensitive to the spectral region of the light source mainly responsible for producing degradation in the test materials to provide the most meaningful evaluation of exposure test consistency. The weathering reference material should also...
SCOPE
1.1 This standard describes the criteria to be used for selection of a weathering reference material (WRM) and procedures to be used for determining within lab and between lab tolerances of changes in measured properties of weathering reference materials. This standard also describes a procedure for comparing different lots of the same type of a weathering reference material.  
Note 1: Examples of laboratory accelerated tests in which a weathering reference material could be used to monitor consistency are exposure tests such as those described in Practices G152, G153, G154, and G155and other standards in which tests conducted according to these standards are referenced. Examples of outdoor exposures where a weathering reference material could be used to monitor consistency are those conducted according to Practices G7, G24, or G90. A reference material can also be used to monitor consistency of exposure or conditioning test that do not involve exposure to light.  
1.2 Weathering reference materials are most often used to (1) monitor consistency (that is, repeatability, reproducibility, or both) of exposure tests, (2) to determine the time or radiant exposure at which test materials are evaluated, (3) as a reference material for comparing to test materials exposed at the same time. Weathering reference materials cannot be used to classify or characterize the relative severity of any exposure test because of the large variability in material responses to the effects of light, heat, and water.  
1.3 This practice does not cover control materials which, by definition are selected to be of similar composition and construction to the test materials, and are exposed at the same time as test materials.  
1.4 This practice provides an outline of experiments required to determine how the measured properties of the reference material change as a function of exposure to specified test conditions. It includes establishment of re...

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