基本信息
| 标准名称： | ＮＦ１５３５型脉冲信号发生器 |
| 英文名称： | Pulse signal generators for Type NF1535 |
| 中标分类： |
石油 >>
石油综合 >>
技术管理 |
| 发布部门： | 中华人民共和国机械电子工业部 |
| 发布日期： | 1991-04-02 |
| 实施日期： | 1991-07-01 |
| 首发日期： | 1900-01-01 |
| 作废日期： | 2010-01-20 |
| 起草单位： | 南通电子仪器厂 |
| 出版日期： | 1991-07-01 |
| 页数： | 9页 |
适用范围
本标准规定了NF 1535型脉冲信号发生器的技术要求，试验方法和检验规则等内容。本标准适用于NF 1535型脉冲信号发生器，是NF1535型脉冲信号发生器生产和使用的共同技术依据。
前言
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目录
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引用标准
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所属分类： 石油 石油综合 技术管理
【英文标准名称】:Acoustics-Determinationofsoundpowerradiatedintoaductbyfansandotherair-movingdevices-In-ductmethod
【原文标准名称】:声学.风机和其他风动设备辐射入管道中的声功率的测定.管道法
【标准号】:ISO5136-2003
【标准状态】:现行
【国别】:国际
【发布日期】:2003-04
【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/TC43
【标准类型】:()
【标准水平】:()
【中文主题词】:试验;声级;噪声(环境的);声学;噪声测量;声学试验;测定;定义;通风机;声强;导管风扇
【英文主题词】:Acousticmeasurement;Acoustictesting;Acoustics;Definitions;Determination;Ductmethods;Ductedfans;Fans;Loudnesslevels;Measurement;Measuringresults;Measuringtechniques;Noise(environmental);Noisemeasurements;Powerlevels;Sound;Soundintensity;Soundlevel;Soundlevels;Soundpower;Testing;Ventilators;Volume(sound)
【摘要】:1GeneralThisInternationalStandardspecifiesamethodfortestingductedfansandotherair-movingdevicestodeterminethesoundpowerradiatedintoananechoicallyterminatedductontheinletand/oroutletsideoftheequipment.NOTE1Forthesakeofbrevity,wherevertheterm"fan"occursinthetext,itmeans"fanorotherair-movingdevice".Themethodisapplicabletofanswhichemitsteady,broad-band,narrow-bandanddiscrete-frequencysoundandtoairtemperaturesbetween-50℃and+70℃.Thetestductdiameterrangeisfrom0,15mto2m.Testmethodsforsmall(d<0,15m)andlarge(d>2m)testductsaredescribedintheinformativeAnnexesHandI,respectively.Themaximummeanflowvelocityatthemicrophoneheadforwhichthemethodissuitabledependsonthetypeofmicrophoneshieldused,andisasfollows:—foamball15m/s;—nosecone20m/s;—samplingtube40m/s.Abovethesevaluesthesuppressionofturbulentpressurefluctuationsbythemicrophoneshield(see3.9)maybeinsufficient.ItisexpectedthatsoundpowertestswillbeconductedinconjunctionwithairflowperformancetestsinaccordancewithISO5801.Theductingarrangementwillthereforenormallyincorporatea"star"typeflowstraightenerontheoutletsideofthefanwhichwillminimizeswirl(see7.3).Whereitispermissibletodeletethestraighteneras,forexample,withlargefanstoinstallationcategoryCaccordingtoISO5801:1997,themethodislimitedtoaswirlangleof15°(AnexampleofamethodfordeterminingtheangleofswirlisgiveninAnnexJ.)NOTE2TheinstallationcategoriesdefinedinISO5801implythatthefaniseitherductedontheoutletsideonly(categoryB),ontheinletsideonly(categoryC)oronbothsides(categoryD).2TypesofsoundsourceThemethoddescribedinthisInternationalStandardisapplicabletoasoundsourceinwhichafanisconnectedtoductsonatleastoneside.Itisalsoapplicabletootherfan/attenuatorcombinationsorequipmentincorporatingfanswhichcanbeconsideredas"blackboxes".ExamplesoffansandotherequipmentcoveredbythisInternationalStandardare—ductedcentrifugalfans,—ductedaxialflowfans,—ductedmixed-flowfans,—ductedair-handlingunits,—ducteddust-collectionunits,—ductedair-conditioningunits,and—ductedfurnaces.ThisInternationalStandardisalsoapplicabletootheraerodynamicsourcessuchasboxes,dampersandthrottledevicesprovidedthataquietairflowdeliveredbyanauxiliaryfanisavailable,andthesignal-to-noiseratioofsoundpressurestoturbulentpressurefluctuationsinthetestductisatleast6dB(see7.2.1).Analternativemethodtodeterminethesoundpowerleveloftheflow-generatednoiseofsuchaerodynamicsoundsources,whichdoesnotrequirethemeasurementofsoundpressureinaflowenvironment,isdescribedinISO7235.Themethodwasoriginallydevisedforthedeterminationoftheflownoiselevelofductedsilencers.Thesoundpowerisdeterminedinareverberationroomconnectedtothetestductviaatransitionelement.Inthecaseofductedfanswithcloselycoupledattenuators,thesignal-to-noiseratioofsoundpressurestoturbulentpressuresmaybeinsufficientwhenusingthein-ductmethod.ThereforethemethoddescribedinISO7235isrecommendedforsuchfan/attenuatorcombinations.ThisInternationalStandardisnotapplicabletonon-ductedfansorequipment.
【中国标准分类号】:Z32
【国际标准分类号】:17_140_20;23_120
【页数】:68P;A4
【正文语种】:英语