ASTM_G_156_-_09.pdf

Designation:G15609Standard Practice forSelecting and Characterizing Weathering ReferenceMaterials1This standard is issued under the fixed designation G156;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This standard describes the criteria to be used forselection of a weathering reference material(WRM)andprocedures to be used for determining within lab and betweenlab tolerances of changes in measured properties of a referencematerials.This standard also describes a procedure for com-paring different lots of the same type of a reference material.NOTE1Examples of laboratory accelerated tests in which a weather-ing reference material could be used to monitor consistency are exposuretests such as those described in Practices G152,G153,G154,andG155and other standards in which tests conducted according to thesestandards are referenced.Examples of outdoor exposures where a weath-ering reference material could be used to monitor consistency are thoseconducted according to Practices G7,G24,or G90.A reference materialcan also be used to monitor consistency of exposure or conditioning testthat do not involve exposure to light.1.2 Weathering reference materials are most often used to(1)monitor consistency of conditions in exposure tests,(2)todetermine the time or radiant exposure at which test materialsare evaluated,(3)as a reference material for comparing to testmaterials exposed at the same time.Weathering referencematerials cannot be used to classify or characterize the relativeseverity of any exposure test because of the large variability inmaterial responses to the effects of light,heat,and water.1.3 This practice does not cover control materials which,bydefinition are selected to be of similar composition andconstruction to the test materials,and are exposed at the sametime as test materials.1.4 This practice provides an outline of experiments re-quired to determine how the measured properties of thereference material change as a function of exposure to specifiedtest conditions.It includes establishment of reproducible mea-surement procedures,determination of the critical spectralregion in the light source causing the changes,and effects ofother critical exposure stresses such as temperature and mois-ture.2.Referenced Documents2.1 ASTM Standards:2E177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE1169 Practice for Conducting Ruggedness TestsG7 Practice for Atmospheric Environmental Exposure Test-ing of Nonmetallic MaterialsG24 Practice for Conducting Exposures to Daylight FilteredThrough GlassG90 Practice for Performing Accelerated Outdoor Weather-ing of Nonmetallic Materials Using Concentrated NaturalSunlightG113 Terminology Relating to Natural and Artificial Weath-ering Tests of Nonmetallic MaterialsG152 Practice for Operating Open Flame Carbon Arc LightApparatus for Exposure of Nonmetallic MaterialsG153 Practice for Operating Enclosed Carbon Arc LightApparatus for Exposure of Nonmetallic MaterialsG154 Practice for Operating Fluorescent LightApparatus forUV Exposure of Nonmetallic MaterialsG155 Practice for Operating Xenon Arc Light Apparatus forExposure of Non-Metallic MaterialsG178 Practice for Determining the Activation Spectrum of aMaterial(Wavelength Sensitivity to an Exposure Source)Using the Sharp Cut-On Filter or Spectrographic Tech-nique2.2 SAE Standard:SAE J1960,Accelerated Exposure of Automotive ExteriorMaterials using a Controlled Irradiance Water-CooledXenon Arc Apparatus3SAE J1885,Accelerated Exposure of Automotive InteriorMaterials Using a Controlled Irradiance Water-CooledXenon Arc Apparatus31This practice is under the jurisdiction ofASTM Committee G03 on Weatheringand Durability and is the direct responsibility of Subcommittee G03.01 on JointWeathering Projects.Current edition approved June 1,2009.Published July 2009.Originally approvedin 1997.Last previous edition approved in 2002 as G15602.DOI:10.1520/G0156-09.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from Society of Automotive Engineers(SAE),400 CommonwealthDr.,Warrendale,PA 15096-0001,http:/www.sae.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.Terminology3.1 DefinitionsThe definitions listed in Terminology G113are applicable to this standard.4.Significance and Use4.1 Weathering reference materials are used in laboratoryaccelerated exposure tests to verify consistency among testsrun at different times and