Product Code:SAE AS4801
Title:Hose Assembly, Lined Silicone, 125 psi, Fixed Cavity Coupling, Potable Water, Straight Female to 90掳 Female
Issuing Committee:G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies
Scope:Scope unavailable.【英文标准名称】:StandardGuideforMixedFlowingGas(MFG)TestsforElectricalContacts
【原文标准名称】:电触点的混流气体试验用标准指南
【标准号】:ASTMB845-1997(2008)e1
【标准状态】:现行
【国别】:美国
【发布日期】:1997
【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】:B02.11
【标准类型】:(Guide)
【标准水平】:()
【中文主题词】:
【英文主题词】:acceleratedtest;airvelocity;atmosphericcorrosion;chlorine;connector;corrosion;corrosivegastesting;electricalcontacts;environmental;humidity;hydrogensulfide;mixedflowinggas;nitrogendioxide;pollutant;reliability;sulfur;sulfurdioxi
【摘要】:Preservationofaconductingsurfaceonelectricalcontactisvitaltothecontinuedfunctioningofsuchcontacts.Contaminationofthesurfacewithinsulatinglayersformedbycorrosionprocessesisonepotentialhazard.LaboratorytestingofcontactsinMFGtestsisusedtoassesstheeffectivenessofdesignfeaturesandmaterials.MFGtestsareusedindevelopmentstudiesofprocessesandmaterialsforcontacts.Forexample,couponspecimensmaybeexposedtoMFGteststoevaluatenewcontactmaterials,layersofnewcoatingmaterialsonasupportingsubstrate,reducedcoatingthicknesses,orprotectivesurfacetreatments.MFGtestsarealsoemployedtotestthedurabilityofafinishedproductwithrespecttoatmosphericcorrosion.Forexample,finishedconnectorsmaybeexposedtoaMFGtestandtheirperformancescomparedagainsteachotheroragainstasetoffixedrequirements.Relaysorswitchcontactsmaybeexposedintheoperatedandnon-operatedconditionstocompareperformance.MFGtestsareusefulfordeterminingtheeffectivenessofconnectorhousingsandshroudsasbarrierstoingressofatmosphericcorrodantstothecontactsurfaces.Thesetestscanalsobeusedtoassessthescreeningofthemetal-to-metalcontactareasofmatedconnectors.MFGtestsareemployedasqualificationteststodetermineconnectorfailureratesinapplicationenvironmentsforwhichcorrelationbetweentestandapplicationhaspreviouslybeenestablished.ThisguideprovidestestconditionswhicharetobeappliedinconjunctionwithPracticeB827whichdefinestherequiredtestoperationandcertificationprocedures,tolerances,andreportingrequirements.WherethetestspecifierrequirescertificationsortolerancesdifferentthanthoseprovidedinPracticeB827,therequiredcertificationsortolerancesshallbepartofthetestspecification.DifferencesfromthespecificationsinPracticeB827shallbereportedinthetestreportprovidedbythetestoperatortothetestspecifier.Specificationofoneofthetestconditionsdefinedinthisdocumentintheformofastatementsuchas,x201C;PartsshallbetestedinaccordancewithASTMB845MethodZ.x201D;,implicitlyrequirestestcondition,Z,appliedaccordingtoPracticeB827.1.1Thetechniquesdescribedinthisguidepertaintomixedflowinggas(MFG)testscontainingspeciesthatareappliedtoevaluatedevicescontainingelectricalcontactssuchassliprings,separableconnectors,electromechanicalrelaysorswitchcontacts.Thesetechniquesmayberelevanttootherdevices,butitistheresponsibilityoftheusertodeterminesuitabilitypriortotesting.1.2TheMFGtestsdescribedinthisguidearedesignedtoacceleratecorrosivedegradationprocesses.Theseaccelerationsaredesignedsuchthatthedegradationoccursinamuchshortertimeperiodthanthatexpectedforsuchprocessesintheintendedapplicationenvironmentofthedevicebeingtested.Applicationenvironmentscanvarycontinuouslyfrombenigntoaggressivelycorrosive.Connectorsandcontactswithinclosedelectroniccabinetsmaybeaffectedbyanenvironmentofdifferentseveritythantheenvironmentontheoutsideofsuchcabinets.Ingeneral,indoorenvironmentsaredifferentthanoutdoorenvironments.TheMFGtestsdescribedherein,beingdiscreteembodimentsofspecificcorrosiveconditions,cannotberepresentativeofallpossibleapplicationenvironments.Itistheresponsibilityofthetestspecifiertoassurethepertinenceofagiventestconditiontothespecifier''sapplicationcondition.1.3TheMFGtestsdescribedhereinarenotd......
【中国标准分类号】:K14
【国际标准分类号】:29_120_20
【页数】:11P.;A4
【正文语种】:英语