【英文标准名称】:StandardPracticeforConstructionofaSteppedBlockandItsUsetoEstimateErrorsProducedbySpeed-of-SoundMeasurementSystemsforUseonSolids
【原文标准名称】:阶梯形砌块的结构和固体用声速测量系统对砌块进行检验产生的评估错误
【标准号】:ASTME1544-1999(2004)e1
【标准状态】:现行
【国别】:
【发布日期】:1999
【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】:E28.13
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:超声检验;无损检验;玻璃;试验
【英文主题词】:acousticvelocity;elasticmoduli;materialscharacterization;referencestandard;residualstress;speedofsound;stressmeasurement;ultrasonics
【摘要】:Theuseofsoundspeedvaluestodeterminechangesintheelasticconstantsduetoappliedorresidualstressrequiresthatsuchmeasurementsbeofhighprecisionandlowbias.Forthatreason,specialevaluationteststodeterminearepresentativeprecisionandbiasforthespecifictechnique,method,andequipmentsetupusedaregiven.Speedofsoundisameasurethatdependsontheaccuratemeasurementsoflengthofpathoftravelandtransittimeorotherrelatedparameterssuchasfrequency,etc.Bothmeasurementsaresubjecttocertaininterpretationsandassumptionsandarehighlydependentonlaboratoryexpertise.Thispracticeprovidesameansofcheckingoveralltechnique.Thispracticeshallbeusedwhenitisnecessarytoassessthesystematicandrandomerrorsassociatedwithaparticularspeedofsoundmeasurementinasolidmedium.Itcanbeusedtocheckbothequipmentperformanceandmeasurementtechniquefortheseerrors.Itcanalsobeusedtostudyinherenterrorsinaparticularmethod.ItcanalsobeusedtoassessproposedcorrectionstosoundspeedmeasurementssuchasthephasecorrectionsofPapadakis(3,4).Theresultantprecisionandbiasdeterminedbytheuseofthedescribedblockrepresentsamoreidealsituationthanthesamemeasurementperformedinpractice,inthefield.Thus,theerrorforthespecificfieldmeasurementmaybelargerthanindicatedbythistest.Thistestrepresentsthebesterrorconditionforagiventechniqueandpractice.1.1Thispracticeprovidesameansforevaluatingbothsystematicandrandomerrorsforultrasonicspeed-of-soundmeasurementsystemswhichareusedforevaluatingmaterialcharacteristicsassociatedwithresidualstressandwhichmayalsobeusedfornondestructivemeasurementsofthedynamicelasticmoduliofmaterials.Importantfeaturesandconstructiondetailsofareferenceblockcrucialtotheseerrorevaluationsaredescribed.Thispracticecanbeusedwhenevertheprecisionandbiasofsoundspeedvaluesareinquestion.1.2Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:Q17
【国际标准分类号】:
【页数】:6P.;A4
【正文语种】:


【英文标准名称】:FixedRadioSystems-MultipointEquipmentandAntennas-Part2:HarmonizedENcoveringtheessentialrequirementsofarticle3.2oftheR&TTEDirectiveforDigitalMultipointRadioEquipment(EndorsementoftheEnglishversionEN302326-2V1.1.1(2005-1
【原文标准名称】:固定无线电系统.多点设备和天线.第2部分:符合EN的包括多点无线电设备的R和TTE指令第3.2章基本要求
【标准号】:DINEN302326-2-2006
【标准状态】:作废
【国别】:德国
【发布日期】:2006-06
【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】:天线;频带;传播技术;数字工程;数字信号;电气工程;频率;频率范围;信息处理;机械性能;;无线电工程;无线电通信链路;无线电装置;无线电中继系统;卫星通信链路;信号传输;规范(验收);电信;远程通信;传输技术
【英文主题词】:
【摘要】:
【中国标准分类号】:M51
【国际标准分类号】:33_060_30
【页数】:2P;A4
【正文语种】:德语