ASTM G141-96

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: G 141 – 96
Standard Guide for
Addressing Variability in Exposure Testing on Nonmetallic
1
Materials
This standard is issued under the fixed designation G 141; 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 (e) 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
controlling the laboratory testing environment, and the variability in the measurement of performance.
It is extremely difficult to compare “absolute data”, that is, color shift, gloss, tensile, and elongation,
and so forth, from different exposure tests. This is true for natural and accelerated exposures conducted
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 G 7 Practice for Atmospheric Environmental Exposure
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Testing of Nonmetallic Materials
1.1 This guide covers information on sources of variability
G 23 Practice for Operating Light-Exposure Apparatus
and strategies for its reduction in exposure testing, and for
(Carbon-Arc Type) With and Without Water for Exposure
taking variability into consideration in the design, execution,
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of Nonmetallic Materials
and data analysis of both exterior and laboratory accelerated
G 24 Practice for Conducting Exposures to Daylight Fil-
exposure tests.
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tered Through Glass
1.2 The values stated in either inch-pound or SI units are to
G 26 Practice for Operating Light-Exposure Apparatus
be regarded separately as the standard. The values given in
(Xenon-Arc Type) With and Without Water for Exposure
parentheses are for information only.
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of Nonmetallic Materials
1.3 This standard does not purport to address all of the
G 53 Practice for Operating Light- and Water-Exposure
safety concerns, if any, associated with its use. It is the
Apparatus (Fluorescent UV-Condensation Type) for Expo-
responsibility of the user of this standard to establish appro-
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sure of Nonmetallic Materials
priate safety and health practices and determine the applica-
G 90 Practice for Performing Accelerated Outdoor Weath-
bility of regulatory limitations prior to use.
ering of Nonmetallic Materials Using Concentrated Natu-
3
2. Referenced Documents
ral Sunlight
G 147 Practice for Conditioning and Handling of Nonme-
2.1 ASTM Standards:
3
2
tallic Materials for Natural and Artificial Weathering Tests
D 4853 Guide for Reducing Test Variability
E 177 Practice for Use of the Terms Precision and Bias in
3. Terminology
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ASTM Test Methods
3.1 Definitions:
E 691 Practice for Conducting an Interlaboratory Study to
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3.1.1 Terminology G 113 is generally applicable to this
Determine the Precision of a Test Method
guide.
4. Significance and Use
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This guide is under the jurisdiction of ASTM Committee G-3 on Durability of
Nonmetallic Materials and is the direct responsibility of Subcommittee G03.93 on
4.1 Many standards and specifications reference exposure
Statistics.
tests performed according to standards that are the responsi-
Current edition approved July 10, 1996. Published December 1996.
2 bility of Committee G-3 on Durability of Nonmetallic Mate-
Annual Book of ASTM Standards, Vol 07.01.
3
Annual Book of ASTM Standards, Vol 14.02. rials. In many cases, use of the data generated in these tests
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
G 141
fails to consider the ramifications of variability in the exposure the same solar-ultraviolet radiation dose may not give the same
test practices. This variability can have a profound effect on the degree of change unless the heat and moisture levels are also
interpretation of results from the exposure tests, and if not identical.
taken into consideration in test design and data analysis, can 5.2.1 Another problem related to timing exposures by
lead to erroneous or misleading conclusions. This guide lists broad-band radiation measurements is that so
...