DIN EN 13513-2002 鞋类.鞋帮的试验方法.可形变度;德文版本EN13513:2001

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MIL-P-46463C (NOTICE 2), MILITARY SPECIFICATION: PRIMER, PERCUSSION, M71A1 PARTS FOR (01 JUN 1996)., MIL-P-46463C, including Amendment 1 and Notice 1, dated 01 September 1988, is hereby canceled without replacement.【英文标准名称】:StandardTestMethodsforMeasuringResistanceofElectricalConnections(StaticContacts)
【原文标准名称】:电气连接的接触电阻的测量方法(静态接触)
【标准号】:ASTMB539-2002(2008)
【标准状态】:现行
【国别】:美国
【发布日期】:2002
【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】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:connectionresistance;connectors;contactresistance;contacts;electricalresistance;junctionresistance;lowlevelcontactresistance;separableconnections;Electricalresistance/resistivity--electricalcontactmaterials;Connectors;Contactresistan
【摘要】:p>AsstatedinTerminologyB542,contactresistanceiscomprisedofaconstrictionresistanceandafilmresistance.Whenpresent,thelatteroftheseisusuallymuchgreaterinvalueanddominatesthecontactresistance.Foragivencontactspot,whenthefilmresistanceiszeroornegligiblethecontactresistanceforthatspotisnearlythesameastheconstrictionresistanceandtherefore,asapracticalmatter,hasaminimumvaluewhichrepresentsacleanmetal-to-metalcontactspot.Asrealcontactsurfacesexhibitvaryingdegreesofroughness,realcontactsarenecessarilycomposedofmanycontactspotswhichareelectricallyparallel.Inpracticalcasesthecleanmetal-to-metalcontactspotswillcarrymostofthecurrentandthetotalcontactresistanceisprimarilydependentonthesizeandnumberofmetalliccontactspotspresent(seeNote1).Inaddition,acceptablylowvaluesofcontactresistanceareoftenobtainedwithtrueareasofcontactbeingsignificantlylessthantheapparentcontactarea.Thisistheresultofhavingalargenumberofsmallcontactspotsspreadoutoverarelativelylargeapparentcontactarea.Note18212;Thetermmetalliccontactasusedhereisintendedtoincludethesocalledquasi-metalliccontactspotsaswell.ThelattercasewasdiscussedinElectricContactsbyHolm.Thepracticalevaluationandcomparisonofelectricalconnectionsdependinlargepartontheircontactresistancecharacteristics.Ontheonehand,theabsolutevalueofcontactresistanceisgreatlydependentontheamountofmetalliccontactestablishedandindicatesinitiallyhowefficientthesystemisinproducingareasofmetalliccontact.Ontheotherhand,acomparisonoftheinitialresistancetotheresistanceafteragingindicateshowstablethesystemisinmaintainingtheinitialcontactarea.Bothofthesecharacteristicsshouldbeconsideredwhenevaluatingcontactsystems.Thecriteriaemployedinevaluatingcontactresistanceandstabilityarenotapartofthesetestmethodsastheydependonspecificapplicationsandtherefore,willnotbequantitativelystated.However,anestimateofcontactresistanceresultingfromgoodmetalliccontactcanbemadeforagivenphysicalsituationandusedasacomparisontoactualmeasurementstodeterminehoweffectivethesystemisinestablishingstablemetalliccontact.Resistancesmeasuredbythesemethodsbefore,duringandaftersimulatedlifetestsareusedasameansofdeterminingthestabilityofcontactswithinadevice.1.1Thesetestmethodscoverequipmentandtechniquesformeasuringtheresistanceofstaticelectricalconnectionssuchaswireterminationsorsplices,frictionconnectors,solderedjoints,andwrapped-wireconnections.1.2Measurementsundertwodistinctlevelsofelectricalloadingaredescribed.Theselevelsare:(1)drycircuit,(2)andratedcurrent.Oneorbothoftheselevelsofloadingmayberequiredinspecificcases.1.3Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.ItistheresponsibilityoftheuserofthisstandardtobecomefamiliarwithallhazardsincludingthoseidentifiedintheappropriateMaterialSafetyDataSheet(MSDS)forthisproduct/materialasprovidedbythemanufacturer,toestablishappropriatesafetyandhealthpractices,anddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:K04
【国际标准分类号】:29_120_20
【页数】:6P.;A4
【正文语种】:英语