ASTM_G_178_-_16.pdf

Designation:G17816Standard Practice forDetermining the Activation Spectrum of a Material(Wavelength Sensitivity to an Exposure Source)Using theSharp Cut-On Filter or Spectrographic Technique1This standard is issued under the fixed designation G178;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 practice describes the determination of the relativeactinic effects of individual spectral bands of an exposuresource on a material.The activation spectrum is specific to thelight source to which the material is exposed to obtain theactivation spectrum.A light source with a different spectralpower distribution will produce a different activation spectrum.1.2 This practice describes two procedures for determiningan activation spectrum.One uses sharp cut-on UV/visibletransmitting filters and the other uses a spectrograph todetermine the relative degradation caused by individual spec-tral regions.NOTE1Other techniques can be used to isolate the effects ofindividual spectral bands of a light source,for example,interferencefilters.1.3 The techniques are applicable to determination of thespectral effects of solar radiation and laboratory acceleratedtest devices on a material.They are described for the UVregion,but can be extended into the visible region usingdifferent cut-on filters and appropriate spectrographs.1.4 The techniques are applicable to a variety of materials,both transparent and opaque,including plastics,paints,inks,textiles and others.1.5 The optical and/or physical property changes in amaterial can be determined by various appropriate methods.The methods of evaluation are beyond the scope of thispractice.1.6 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.NOTE2There is no ISO standard that is equivalent to this standard.2.Referenced Documents2.1 ASTM Standards:2D256 Test Methods for Determining the Izod PendulumImpact Resistance of PlasticsD638 Test Method for Tensile Properties of PlasticsD822 Practice for Filtered Open-Flame Carbon-Arc Expo-sures of Paint and Related CoatingsD1435 Practice for Outdoor Weathering of PlasticsD1499 Practice for Filtered Open-Flame Carbon-Arc Expo-sures of PlasticsD2244 Practice for Calculation of Color Tolerances andColor Differences from Instrumentally Measured ColorCoordinatesD2565 Practice for Xenon-Arc Exposure of Plastics In-tended for Outdoor ApplicationsD4141 Practice for Conducting Black Box and Solar Con-centrating Exposures of CoatingsD4329 Practice for Fluorescent Ultraviolet(UV)Lamp Ap-paratus Exposure of PlasticsD4364 Practice for Performing Outdoor Accelerated Weath-ering Tests of Plastics Using Concentrated SunlightD4459 Practice for Xenon-Arc Exposure of Plastics In-tended for Indoor ApplicationsD4508 Test Method for Chip Impact Strength of PlasticsD4587 Practice for Fluorescent UV-Condensation Expo-sures of Paint and Related CoatingsD5031 Practice for Enclosed Carbon-Arc Exposure Tests ofPaint and Related CoatingsD6360 Practice for Enclosed Carbon-Arc Exposures of Plas-ticsD6695 Practice for Xenon-Arc Exposures of Paint andRelated CoatingsE275 Practice for Describing and Measuring Performance ofUltraviolet and Visible SpectrophotometersE313 Practice for Calculating Yellowness and WhitenessIndices from Instrumentally Measured Color Coordinates1This 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 Feb.1,2016.Published February 2016.Originallyapproved in 2003.Last previous edition approved in 2009 as G178 09.DOI:10.1520/G0178-16.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 E925 Practice for Monitoring the Calibration of Ultraviolet-Visible Spectrophotometers whose Spectral Bandwidthdoes not Exceed 2 nmG7 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 MaterialsG147 Practice for Conditioning and Handling of Nonmetal-lic Materials for Natural and