UL SUBJECT 497E-2008 天线引入线导线用防护罩调查大纲.发布编号:2

作者:标准资料网 时间:2024-05-12 03:15:11   浏览:9596   来源:标准资料网
下载地址: 点击此处下载
【英文标准名称】:OUTLINEOFINVESTIGATIONFORPROTECTORSFORANTENNALEAD-INCONDUCTORSIssueNo.2
【原文标准名称】:天线引入线导线用防护罩调查大纲.发布编号:2
【标准号】:ULSUBJECT497E-2008
【标准状态】:现行
【国别】:美国
【发布日期】:2008-06-05
【实施或试行日期】:
【发布单位】:美国保险商实验所(US-UL)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:
【英文主题词】:
【摘要】:1.1ThisOutlineofInvestigationcoversprotectorsforantennalead-inconductors.Thesedevicesareusedtolimitsurgesonthecablethatconnectstheantennatothereceiver/transmitterelectronicsandareconnectedbetweentheconductorsandthegroundedshieldorothergroundconnection.Typicalapplicationsincludeantennainstallationsforradioandtelevisionreceivingequipment,amateurradiotransmittingandreceivingequipment,cellulartelephonetowersandWiMaxorWiFiwirelessnetworks.1.2Ascoveredbytheserequirements,protectorsforantennalead-inconductorstypicallyconsistsofairgaparresters,gastubearresters,solid-statearrestersorquarter-wavestubtypedevices,orcombinationsofthesedevices.Othertechnologiesarenotexcluded.Theymayormaynotcontainadditionalcomponentssuchasinductorsorblockingcapacitors.Theseprotectorsareintendedtoprotectequipment,wiring,andpersonnelatthepremisesagainsttheeffectsofexcessivepotentialsandcurrentsontheconductorscausedbylightning.1.3Thesedevicesoperatetodivertasurgecurrenttoearth,andcontroltheresidualvoltage(alsoknownaslet-throughvoltage)toasuitablelevel.Oncethesurgecurrenthassubsided,thedeviceautomaticallyreturnsnormaloperationandresettoastatereadytoreceivethenextsurge.Residualvoltagelimitsortheirsuitabilitytominimizedamagetoconnectedequipmentisnotwithinthescopeoftheserequirements.1.4Theseprotectorsareinvestigatedfortheirmaximumdischargecurrent(Imax)capabilityusingan8/20currentwaveform.Thisisthemaximumimpulsecurrenttheprotectorcanwithstand,includingafterenvironmentalconditioning,withoutaffectingitssurgelimitingcapabilityorcreatingariskoffire,fragmentationorelectricalshock.1.5ThisOutlinedoesnotcoverthefollowing:a)Lightningprotectivedevicesfortheprotectionofsecondarydistributionwiringsystemsandequipment.b)AntennadischargeunitsforradioandtelevisionreceivingappliancesthatarecoveredbytheStandardforAntenna-DischargeUnits,UL452.c)Lightningconductorandairterminalsforconnectionoflightningrodsforbuildingprotection.d)ProtectorsforfirealarmsignalingcircuitsthatarecoveredbytheStandardforProtectorsforDataCommunicationsandFire-AlarmCircuits,UL497B.e)EquipmentcoveredbytheStandardforSecondaryProtectorsforCommunicationsCircuits,UL497A.f)EquipmentcoveredbytheStandardforSurgeProtectiveDevices,UL1449.g)EquipmentcoveredbytheStandardforProtectorsforPaired-ConductorCommunicationsCircuits,UL497.h)EquipmentcoveredbytheStandardforProtectorsforCoaxialCommunicationsCircuits,UL497C.i)DCblockingconnectorsorcomponentsthatdonothavelightningprotectionastheirprimaryfunction.j)Applicationswherefollow-oncurrentsmayoccur,suchasinstallationswherecommunicationswiringisroutedonsharedfacilitieswithelectricaldistributionsystems.1.6Specialinstallationmethodsarerequiredforequipmentconnectedtowire-linecommunicationfacilitiesservinghigh-voltageelectricpowerstationsoperatingatgreaterthan1kV.Theserequirementsdonotcovertheequipmentordevicesusedinthedesignofsuchinstallations.Specialsystemdesignrequirements,suchasthosecoveredbyRecommendedPracticefortheProtectionofWire-LineCommunicationFacilitiesServingElectricPowerLocations,IEEE487,shallbefollowedtoreducetherisksassociatedwithwire-linecommunicationfacilitiesservingsuchpowerstations.
【中国标准分类号】:M51
【国际标准分类号】:
【页数】:26P.;A4
【正文语种】:英语


下载地址: 点击此处下载
【英文标准名称】:Generalpurposeboltsandscrews-Metricseries-Radiiunderthehead
【原文标准名称】:普通螺栓和螺钉米制系列头下圆角半径
【标准号】:ISO885-2000
【标准状态】:现行
【国别】:国际
【发布日期】:2000-03
【实施或试行日期】:
【发布单位】:国际标准化组织(IX-ISO)
【起草单位】:ISO/TC2
【标准类型】:()
【标准水平】:()
【中文主题词】:米制螺纹;厘米克秒制;半径;端头(紧固件);内径;总论;螺钉;使用;尺寸;紧固件;螺栓
【英文主题词】:Applications;Bolts;CGSsystem;Dimensions;Fasteners;Generalsection;Heads(fasteners);Insidediameters;Metricscrewthreads;Radius;Screws(bolts)
【摘要】:ThisInternationalStandardspecifiesthesizesoftheradiiundertheheadandthetransitiondiametersofmetricseriesgeneralpurposeboltsandscrews.
【中国标准分类号】:J13
【国际标准分类号】:21_060_10
【页数】:2P.;A4
【正文语种】:英语


【英文标准名称】:EESSIConformityassessmentguidance-Part4:Signaturecreationapplicationsandproceduresforelectronicsignatureverification;EnglishversionCWA14172-4:2001
【原文标准名称】:EESSI合格评定指南.第4部分:电子签名验证用签名创建应用和程序
【标准号】:DINCWA14172-4-2002
【标准状态】:作废
【国别】:德国
【发布日期】:2002-04
【实施或试行日期】:
【发布单位】:德国标准化学会(DIN)
【起草单位】:
【标准类型】:()
【标准水平】:()
【中文主题词】:定义;电子数据处理;基础设施;保密性能;数据传送;编码;信息技术;数据处理;指导手册;电子系统;规范(验收);电子签名;IT安全;合格证明书;数据保护;合格试验;验证;签字;算法;数据安全;认证
【英文主题词】:
【摘要】:
【中国标准分类号】:L70
【国际标准分类号】:35_240_50;35_040;35_240_60
【页数】:17P;A4
【正文语种】:德语