ASTM G141-09
(Guide)Standard Guide for Addressing Variability in Exposure Testing on Nonmetallic Materials
Standard Guide for Addressing Variability in Exposure Testing on Nonmetallic Materials
SIGNIFICANCE AND USE
Many standards and specifications reference exposure tests performed according to standards that are the responsibility of Committee G03 on Durability of Nonmetallic Materials. In many cases, use of the data generated in these tests fails to consider the ramifications of variability in the exposure test practices. This variability can have a profound effect on the interpretation of results from the exposure tests, and if not taken into consideration in test design and data analysis, can lead to erroneous or misleading conclusions. This guide lists some of the sources for test variability and recommends strategies for executing successful weathering studies. Not all sources of variability in weathering testing are addressed in this guide. Specific materials, sampling procedures, specimen preparation, specimen conditioning, and material property measurements can contribute significantly to variability in weathering test results. Many of these concerns are addressed in Guide G147. To reduce the contribution of an instrumental method to test variability, it is essential to follow appropriate calibration procedures and ASTM standards associated with the particular property measurement. Additional sources of variability in test results are listed in Guide D4853, along with methods for identifying probable causes.
SCOPE
1.1 This guide covers information on sources of variability and strategies for its reduction in exposure testing, and for taking variability into consideration in the design, execution, and data analysis of both exterior and laboratory accelerated exposure tests.
1.2 The values stated in SI units are to be regarded separately as the standard. The inch-pound values given in parentheses are for information only.
1.3 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.
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Designation: G141 − 09
StandardGuide for
Addressing Variability in Exposure Testing of Nonmetallic
1
Materials
This standard is issued under the fixed designation G141; 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.
INTRODUCTION
No experimental procedure is exactly repeatable or reproducible. Exposure testing is susceptible to
poor test reproducibility because of many contributing factors. These include the type of material and
its homogeneity, the complexity and variability of the outdoor environment, difficulty in precisely
controllingthelaboratorytestingenvironment,andthevariabilityinthemeasurementofperformance.
It is extremely difficult to compare “absolute data,” that is, color shift, gloss, tensile, and elongation,
andsoforth,fromdifferentexposuretests.Thisistruefornaturalandacceleratedexposuresconducted
outdoors or for accelerated exposure tests conducted at different times in one laboratory or comparing
results between laboratories. The purpose of this guide is to provide the user with background
information on test variability and guidance to conduct an exposure test that will provide valid and
useful durability information.
1. Scope* D4853 Guide for Reducing Test Variability (Withdrawn
3
2008)
1.1 This guide covers information on sources of variability
D6631 Guide for Committee D01 for Conducting an Inter-
and strategies for its reduction in exposure testing, and for
laboratory Study for the Purpose of Determining the
taking variability into consideration in the design, execution,
Precision of a Test Method
and data analysis of both exterior and laboratory accelerated
E177 Practice for Use of the Terms Precision and Bias in
exposure tests.
ASTM Test Methods
1.2 The values stated in SI units are to be regarded sepa-
E691 Practice for Conducting an Interlaboratory Study to
rately as the standard. The inch-pound values given in paren-
Determine the Precision of a Test Method
theses are for information only.
G7 Practice for Atmospheric Environmental Exposure Test-
ing of Nonmetallic Materials
1.3 This standard does not purport to address all of the
G24 Practice for Conducting Exposures to Daylight Filtered
safety concerns, if any, associated with its use. It is the
Through Glass
responsibility of the user of this standard to establish appro-
G90 Practice for Performing Accelerated Outdoor Weather-
priate safety and health practices and determine the applica-
ing of Nonmetallic Materials Using Concentrated Natural
bility of regulatory limitations prior to use.
Sunlight
G113 Terminology Relating to Natural andArtificial Weath-
2. Referenced Documents
ering Tests of Nonmetallic Materials
2
2.1 ASTM Standards:
G147 Practice for Conditioning and Handling of Nonmetal-
lic Materials for Natural and Artificial Weathering Tests
G151 Practice for Exposing Nonmetallic Materials inAccel-
erated Test Devices that Use Laboratory Light Sources
G152 Practice for Operating Open Flame Carbon Arc Light
1
This guide is under the jurisdiction of ASTM Committee G03 on Weathering
Apparatus for Exposure of Nonmetallic Materials
and Durabilityand is the direct responsibility of Subcommittee G03.93 on Statistics.
G153 Practice for Operating Enclosed Carbon Arc Light
Current edition approved Dec. 1, 2009. Published February 2010. Originally
Apparatus for Exposure of Nonmetallic Materials
approved in 1996. Last previous edition approved in 2003 as G141 – 03. DOI:
10.1520/G0141-09.
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
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.
*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 ----------------------
G141 − 09
G154 PracticeforOperatingFluorescentLightApparatusfor radiation and temperature, and to determine possible effects of
UV Exposure of Nonmetallic Materials moisture. Different exposure sites in one climate (even those in
G155 Practice for Operating XenonArc LightApparatus for close proximity) can cause significantly different results, de-
Exposure of Non-Metallic Materials pending on material.
NOTE 1—Exposures in a tropical summer rain climate (for example,
G166 Guide for Statistical Analysis of Service Life Data
Miami,Florida)andinahotdesertclimate(forexample,Phoenix,AZ)a
...
This document is not anASTM standard and is intended only to provide the user of anASTM 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:G141–03 Designation:G141–09
Standard Guide for
Addressing Variability in Exposure Testing of Nonmetallic
1
Materials
This standard is issued under the fixed designation G141; 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.
INTRODUCTION
No experimental procedure is exactly repeatable or reproducible. Exposure testing is susceptible to
poor test reproducibility because of many contributing factors. These include the type of material and
its homogeneity, the complexity and variability of the outdoor environment, difficulty in precisely
controllingthelaboratorytestingenvironment,andthevariabilityinthemeasurementofperformance.
It is extremely difficult to compare “absolute data,” that is, color shift, gloss, tensile, and elongation,
andsoforth,fromdifferentexposuretests.Thisistruefornaturalandacceleratedexposuresconducted
outdoors or for accelerated exposure tests conducted at different times in one laboratory or comparing
results between laboratories. The purpose of this guide is to provide the user with background
information on test variability and guidance to conduct an exposure test that will provide valid and
useful durability information.
1. Scope*
1.1 This guide covers information on sources of variability and strategies for its reduction in exposure testing, and for taking
variability into consideration in the design, execution, and data analysis of both exterior and laboratory accelerated exposure tests.
1.2 The values stated in SI units are to be regarded separately as the standard. The inch-pound values given in parentheses are
for information only.
1.3 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.
2. Referenced Documents
2
2.1 ASTM Standards:
D4853 Guide for Reducing Test Variability
D6631 Guide for Committee D01 for Conducting an Interlaboratory Study for the Purpose of Determining the Precision of a
Test Method
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
G7
G7 Practice for Atmospheric Environmental Exposure Testing of Nonmetallic Materials
G24 Practice for Conducting Exposures to Daylight Filtered Through Glass
G90 Practice for Performing Accelerated Outdoor Weathering of Nonmetallic Materials Using Concentrated Natural Sunlight
G113 Terminology Relating to Natural and Artificial Weathering Tests of Nonmetallic Materials
G147 Practice for Conditioning and Handling of Nonmetallic Materials for Natural and Artificial Weathering Tests
G151 Practice for Exposing Nonmetallic Materials in Accelerated Test Devices that Use Laboratory Light Sources
G152 Practice for Operating Open Flame Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials
G153 Practice for Operating Enclosed Carbon Arc Light Apparatus for Exposure of Nonmetallic Materials
1
This guide is under the jurisdiction of ASTM Committee G03 on Durability of Nonmetallic MaterialsWeathering and Durability and is the direct responsibility of
Subcommittee G03.93 on Statistics.
Current edition approved Dec. 1, 2003.2009. Published January 2004.February 2010. Originally approved in 1996. Last previous edition approved in 19962003 as
G141–96.G141 – 03. DOI: 10.1520/G0141-039.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*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 ----------------------
G141–09
G154 Practice for Operating Fluorescent Light Apparatus for UV Exposure of Nonmetallic Materials
G155 Practice for Operating Xenon Arc Light Apparatus for Exposure of Non-Metallic Materials
G166 Guide for Statistical Analysis of Service Life Data
G169 GuideforApplicationofBasicStatisticalMethodstoWeatheringTestsGuideforApplicationofBasic
...
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