ASTM G21-1996(2002) 合成聚合材料防霉性的测定

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【英文标准名称】:StandardPracticeforDeterminingResistanceofSyntheticPolymericMaterialstoFungi
【原文标准名称】:合成聚合材料防霉性的测定
【标准号】:ASTMG21-1996(2002)
【标准状态】:现行
【国别】:
【发布日期】:1996
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:G03.04
【标准类型】:(Specification)
【标准水平】:()
【中文主题词】:电阻器;塑料;持久性;非金属;霉菌;材料;高聚物;耐力;测定
【英文主题词】:fungalbiosusceptability;fungaldecay;microbiologicalassay;microbiologicalsusceptability
【摘要】:Thesyntheticpolymerportionofthesematerialsisusuallyfungus-resistantinthatitdoesnotserveasacarbonsourceforthegrowthoffungi.Itisgenerallytheothercomponents,suchasplasticizers,cellulosics,lubricants,stabilizers,andcolorants,thatareresponsibleforfungusattackonplasticmaterials.Itisimportanttoestablishtheresistancetomicrobialattackunderconditionsfavorableforsuchattack,namely,atemperatureof2to38x00B0;C(35to100x00B0;F)andarelativehumidityof60to100%.Theeffectstobeexpectedareasfollows:4.2.1Surfaceattack,discoloration,lossoftransmission(optical),and4.2.2Removalofsusceptibleplasticizers,modifiers,andlubricants,resultinginincreasedmodulus(stiffness),changesinweight,dimensions,andotherphysicalproperties,anddeteriorationofelectricalpropertiessuchasinsulationresistance,dielectricconstant,powerfactor,anddielectricstrength.OftenthechangesinelectricalpropertiesaredueprincipallytosurfacegrowthanditsassociatedmoistureandtopHchangescausedbyexcretedmetabolicproducts.Othereffectsincludepreferentialgrowthscausedbynonuniformdispersionofplasticizers,lubricants,andotherprocessingadditives.Attackonthesematerialsoftenleavesionizedconductingpaths.Pronouncedphysicalchangesareobservedonproductsinfilmformorascoatings,wheretheratioofsurfacetovolumeishigh,andwherenutrientmaterialssuchasplasticizersandlubricantscontinuetodiffusetothesurfaceastheyareutilizedbytheorganisms.Sinceattackbyorganismsinvolvesalargeelementofchanceduetolocalaccelerationsandinhibitions,theorderofreproducibilitymayberatherlow.Toensurethatestimatesofbehaviorarenottoooptimistic,thegreatestobserveddegreeofdeteriorationshouldbereported.Conditioningofthespecimens,suchasexposuretoleaching,weathering,heattreatment,etc.,mayhavesignificanteffectsontheresistancetofungi.Determinationoftheseeffectsisnotcoveredinthispractice.1.1Thispracticecoversdeterminationoftheeffectoffungionthepropertiesofsyntheticpolymericmaterialsintheformofmoldedandfabricatedarticles,tubes,rods,sheets,andfilmmaterials.Changesinoptical,mechanical,andelectricalpropertiesmaybedeterminedbytheapplicableASTMmethods.1.2ThevaluesstatedinSIunitsaretoberegardedasthestandard.Theinch-poundunitsgiveninparenthesesareforinformationonly.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:A29
【国际标准分类号】:83_080_01
【页数】:5P.;A4
【正文语种】:


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【英文标准名称】:Photography-Psychophysicalexperimentalmethodsforestimatingimagequality-Tripletcomparisonmethod
【原文标准名称】:摄影.用心理物理学实验法估计图像质量.三联组比较法
【标准号】:BSISO20462-2-2006
【标准状态】:现行
【国别】:英国
【发布日期】:2006-01-30
【实施或试行日期】:2006-01-30
【发布单位】:英国标准学会(BSI)
【起草单位】:BSI
【标准类型】:()
【标准水平】:()
【中文主题词】:比较;比较方法;定义;估计;评定;实验工作;图象质量;调查条件;摄影;心理生理学;外观检查(试验)
【英文主题词】:Comparison;Comparisonmethods;Definition;Definitions;Estimation;Evaluations;Experimentation;Imagequality;Investigationcondition;Photography;Psychophysiology;Visualinspection(testing)
【摘要】:ISO20462-2:2005definesastandardpsychophysicalexperimentalmethodforsubjectiveimagequalityassessmentofsoftcopyandhardcopystillpictureimages.
【中国标准分类号】:A15
【国际标准分类号】:37_040_01
【页数】:34P.;A4
【正文语种】:英语