【英文标准名称】:Acoustics-Audiometrictestmethods-Soundfieldaudiometrywithpure-toneandnarrow-bandtestsignals
【原文标准名称】:声学.听力试验方法.纯音和窄带试验信号声场测听方法
【标准号】:BSENISO8253-2-2009
【标准状态】:现行
【国别】:英国
【发布日期】:2010-02-28
【实施或试行日期】:2010-02-28
【发布单位】:英国标准学会(GB-BSI)
【起草单位】:BSI
【标准类型】:()
【标准水平】:()
【中文主题词】:声学性质和声学现象;声学;放大;音频信号;听力计;听力测定;听觉阈;校正;封闭式试验室;电气工程;频率;助听器;试验研究;水准仪;收听试验;扬声器;听阈测量;传声器;乱真信号;噪声试验;信号;声音;声场;规范(验收);规范;测试信号;试验;测试条件;试验条件
【英文主题词】:Acousticpropertiesandphenomena;Acoustics;Amplification;Audiosignals;Audiometers;Audiometry;Auditorythreshold;Calibration;Closedtestrooms;Electricalengineering;Frequencies;Hearingaids;Investigations;Levels;Listeningtests;Loudspeakers;Measurementofthresholdofaudibility;Microphones;Noise(spurioussignals);Noisetest;Signals;Sound;Soundfields;Specification(approval);Specifications;Testsignals;Testing;Testingconditions
【摘要】:ThispartofISO8253specifiesrelevanttestsignalcharacteristics,requirementsforfree,diffuse,andquasi-freesoundfields,andproceduresforsoundfieldaudiometryusingpuretones,frequency-modulatedtonesorothernarrow-bandtestsignalspresentedbymeansofoneormoreloudspeakers.Theprimarypurposeisthedeterminationofhearingthresholdlevelsinthefrequencyrange125Hzto8000Hz,butthisrangecanbeextendedto20Hzto16000Hz.ThispartofISO8253doesnotincludespecificationsfortheuseofhand-heldloudspeakers.Speechasatestsignalisnotcovered.ThepurposeofthispartofISO8253istoensurethattestsofhearing,usingsoundfieldaudiometry,giveashighadegreeofaccuracyandreproducibilityaspossible.
【中国标准分类号】:A42
【国际标准分类号】:13_140;17_140_50
【页数】:26P;A4
【正文语种】:英语


【英文标准名称】:StandardTestMethodforSolderabilityofMetallic-CoatedProducts
【原文标准名称】:金属涂覆产品的软钎焊性试验方法
【标准号】:ASTMB678-1986(2011)
【标准状态】:现行
【国别】:
【发布日期】:1986
【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】:B08.10
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:
【摘要】:Inorderthatasoundsolderjointbeformedsimplyandquicklyinaproductionoperation,themoltensoldermustreadilywetandspreadoverthesurfacesoftheproductsbeingjoined.Forthistohappen,thesurfacesmustbecleanorbesoiledonlywithcontaminantsthatareeasilyremovedbyanappropriateflux.Itoftenisnecessarythatthefluxbeonlystrongenoughtoremovethenormallyoccurringsoils.Amoreaggressivefluxmaycorrodetheproductandhaveotherharmfuleffects.Nonactivatedrosininalcoholisthestandardfluxusedinthistestmethod;however,provisionismadefortheuseofotherfluxes.Sincerosinisamildflux,itprovidesbetterdiscriminationbetweenacceptableandunacceptablesolderabilityinmarginalcasesthandomoreactivefluxes.Metalliccoatingsarefrequentlyusedtoprovidesolderablesurfaces.But,animproperlyproducedcoatingmaynotyieldtherequiredsolderability.Therearemanycoatingdefectsthatcausepoorsolderabilityincludingporosity,codepositedimpurities,incorrectthickness,andsurfacecontamination.Itmaybedifficultorimpracticaltotestacoatingdirectlyforeachoftheundesirableconditions.Intheseinstancessolderabilityistested.Productsthatpassthesolderabilitytestcanbeexpectedtosoldersatisfactorilyinproduction.Inthecaseoffailuretopassthetest,thetestresultswillnotrevealthecauseoftheinadequatesolderability,though,withexperience,anoperatormaybeabletoidentifythecause.Thistestmethodmeasurestheabilityofacoatedproducttobesolderedwith60/40tin/leadsolderusinganonactivatedrosinflux.Thissolderandthisflux,oranactivatedformofit,aregenerallyusedintheassemblyofelectronicproducts.Itisintendedthatthetestedspecimensbecomponentsofelectronicproductsorarticleswiththesamegeneralshapeandmass.Articlesthataremuchmoremassivethanthiswillheatuptooslowlyduringthesolderimmersion.Ifmoremassivespecimensaretobetested,alongerimmersiontimewillhavetobeused,thetimetobedeterminedbyexperiment.Ifthespecimentestedislongerthan25mm,itsbottomendwillbeinthesolderforsignificantlylongerthanthespecifiedtime.Therefore,ifthespecimenislongerthan25mm,theresultsobtainedatthebottomendofthespecimenareinvalid.Thispartofthespecimenshallbediscountedintheevaluationoftheresults.Asecondsetoftestscanberunonadditionalspecimensinwhichthespecimensareonlypartlyimmersed.Thesewouldbeusedtoevaluatethebottomends.1.1Thistestmethodprovidesaprocedureforevaluatingthesolderabilityofmetallic-coatedproductsandtestspecimenstoassuresatisfactoryperformanceinmanufacturingprocessesrequiringsolderingwithsoft(tin-lead)solderandrosinflux.Thistestmethodisapplicableonlyfortestingcoatingsthatarenormallyreadilysolderablesuchas:tin,tin-leadalloy,silver,andgold.1.2Thistestmethodisqualitativeandbroadlyapplicable.Itiseasytoperformandrequiresonlysimpleequipment.Thereareothersolderabilitytestsnotcoveredbythistestmethodthataremoreapplicabletospecificsituations,yieldquantitativeresults,orboth.Severalaredescribedintheliterature.Thisisax201C;go-no-gox201D;testanddoesnotgradesolderabilityasexcellent,good,fair,andsoforth.1.3Thisstandardmayinvolvehazardousmaterials,operations,andequipment.Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:
【国际标准分类号】:25_160_50
【页数】:3P.;A4
【正文语种】: