机电专业英语第2版14Unit 14

Unit14Resistor,CapacitorandInductor电阻(diànzǔ)电容和电感精品资料Resistor,

CapacitorandInductor精品资料TranslationReadingMoreTranslatingskillsTextResistor，CapacitorandInductor精品资料

Ifabatteryisconnectedacrossaconductingmaterial，acertainamountofcurrentwillflowthroughthematerial.Thiscurrentisdependentonthevoltageofthebattery,onthe

dimensions

ofthesample,andonthe

conductivityofthematerialitself.1

The

oppositiontocurrentiscalledelectricalresistanceandisrepresentedbythelettersymbolR.Theunitofresistanceistheohm,atermthatisoftenexpressedbyusingΩ.Oneohmisdefinedasthatamountofresistancethatwilllimitthecurrentinaconductorisoneamperewhenthevoltageappliedtotheconductorisonevolt.Largeramountsofresistancearecommonlyexpressedinkiloohm

(KΩ)andinmegohm

(MΩ).

Resistors电阻假若将电池连接在导电材料上，一定数量的电流将流过此材料，流过材料的电流取决于电池的电压、材料的截面积和材料自身的电阻率。对电流的阻力叫电阻，用字母符号R表示。电阻的单位是欧姆．通常用(chánɡyònɡ)表示。l欧姆的定义为：当加到导体上的电压为l伏特时，将导体中的电流限制在1安培所需要的电阻值。较大的电阻值常用(chánɡyònɡ)千欧(KΩ)和百万欧姆(MΩ)表示。精品资料

Theresistorsaremadefrom

carbon

mixtures,metal

films,orresistance

wireandhavetwoconnectingwiresattached.Variableresistors,withanadjustableslidingcontactarm,areoftenusedtocontrol

volume

onradiosandtelevisionsets.电阻可以由碳混合物、金属薄膜或电阻丝制成，它有两个连线接头。常常用带有滑动(huádòng)臂的可变电阻器来控制收音机和电视机的音量。精品资料

Electricalenergycanbestoredinanelectricfield.Thedevicecapableofdoingthisiscalledacapacitorora

condenser.Capacitorsconsistoftwometalplatesthatareseparatedbyall

insulating

material.2

Ifabatteryisconnectedtobothplates,anelectricchargewillflowforashorttimeand

accumulate

oneachplate.Ifthebatteryis

disconnected，thecapacitor

retains

thechargeandthevoltageassociatedwithit.3Capacitors电容器电能可以储存在电场中，能够储存电能的装置叫电容器。电容器是由被绝缘材料分开的两个金属板组成。如果(rúguǒ)电池被连接在两个金属板上，电荷将经过很短的流动而汇集在一个电极板上。假若断开电池，电容器将保持电荷以及与电荷相关的电压。精品资料

Theabilityofacapacitortostoreelectricalenergyistermed

capacitance.

Thecapacitanceisdirectly

proportionaltothe

dielectric

constantofthematerialandtotheareaoftheplatesand

inversely

tothedistanceoftheplates.4Itismeasuredin

farads.Whenachangerofonevoltpersecondacrossitcausesthecurrentofoneamperetoflow,thecondenserissaidtohavethecapacitanceofonefarad.However,faradistoolargeaunittobeusedinradiocalculation,so

microfarad(10-6farads)andthe

picofarad

(10-12farads)aregenerallyused.电容器储存电能的能力叫电容。电容器的电容量与介质的介电常数及平板的面积成正比，与平板间的距离成反比，其大小用法拉表示。当电容器两端的电压以每秒1伏的速率变化，产生的电流为1安培，就称电容器的电容量为1法拉。在无线电方面(fāngmiàn)的计算中，法拉的单位太大，因此常用微法(法拉)和皮法(法拉)。精品资料

Inductorsconsistofaconductingwirewoundintotheformofa

coil.Whenacurrentpassesthroughthecoil,amagneticfieldissetuparounditthattendstoopposerapidchangesincurrent

intensity.5

Allcoilshave

inductance．

Inductor电感电感是由绕成线圈形状的导线组成。当电流(diànliú)通过线圈时，在线圈周围将产生磁场，它将阻止电流(diànliú)的快速变化。一切线圈，都有电感。

精品资料

Acoilofmanyturnswillhavemoreinductancethanoneoffewturns.Alsoifacoilisplacedonaniron

core

itsinductancewillbegreaterthanitwaswithoutthemagneticcore.

Theunitofinduct-anceTheunitofinductanceisthe

henry.Acoilhasaninductanceofonehenryifan

induced

emf

ofonevoltisinducedinthecoilwhenthecurrentthroughitchangesattherateofoneampereparsecond.6Valuesofinductanceusedinradioequipmentvaryoverawiderange.匝数多的线圈比匝数少的线圈电感更大。而且，假若(jiǎruò)线圈中放一个铁芯它的电感将比没有铁芯的线圈的电感更大。电感的单位是亨利。当流过线圈的电流以每秒1安培的速度变化时，如果线圈中感应出1伏特感应电动势，那么，线圈的电感就是1亨利。用于无线电设备的电感值的变化范围很大。精品资料

capacitor[kə'pæsitə]n.电容器capacitance[kə'pæsitəns]n.电容；电流容量inductor[in'dʌktə]n.授职者；感应器inductance[in'dʌktəns]n.感应系数；自感应；电感dimension[di'menʃən,dai-]n.维；尺寸；vt.标出尺寸adj.规格的conductivity[,kəndʌk'tiviti]n.传导性；导电性；传导率opposition[,ɔpə'ziʃən]n.反对；敌对；相反；反对派carbon['ka:bən]n.碳；碳棒；复写纸adj.碳的；碳处理的film[film]n.胶卷；薄膜；轻烟；膜层vi.生薄膜；volume['vɔlju:m]n.体积；卷；册；音量(yīnliàng)；大量；adj.大量的精品资料wire['waiə]n.金属丝；电线；电报vt.拍电报；给……装电线condenser[kən'densə]n.冷凝器；压缩器；聚合器；电容器proportional[prəu'pɔ:ʃənəl]adj.成比例的；相称的，n.比例项insulate['insjuleit]vt.隔离，使孤立；[物]使绝缘，使隔热insulatingadj.绝缘的；隔热的（insulate的ing形式）accumulate[ə'kju:mjuleit]vi.累积；积聚vt.积攒disconnect[,diskə'nekt]vt.拆开(chāikāi)，使分离vi.断开retain[ri'tein]vt.保持；雇；记住dielectric[,daii'lektrik]adj.非传导性的；诱电性的n.电介质；绝缘体inversely['invə:sli]adv.倒转地；相反地；反比例地精品资料farad['færəd]n.法拉（电容单位）microfarad[,maikrəu'færəd]n.微法拉（电容量的实用单位）picofarad['paikəu,færəd]n.微微法拉（百亿分之一法拉）coil[kɔil]vt.盘绕，把……卷成圈vi.成圈状n.卷；线圈intensity[in'tensəti]n.强烈；强度；亮度(liàngdù)；紧张；集中程度core[kɔ:]n.核心；果心；要点；磁心(ironcore铁芯)induced[in'dju:st]adj.感应的；引诱的（induce的过去分词）henry['henri]n.亨(利)[电感单位，略作H]pl.henrys,henries精品资料variableresistor可变电阻器slidingcontact滑动触点dielectricconstant介电常数(jièdiànchánɡshù)，电容率magneticfield磁场emfabbr.n.电动势(ElectromotiveForce)精品资料1.capacitance[kə'pæsitəns]n.电容；电流容量；机械容量1)relatedphrases：inputcapacitance输入电容equivalentcapacitance等效(děnɡxiào)电容capacitancecoupling电容耦合capacitancerelay电容式继电器shantcapacitance分流电容；并联电容anodecapacitance阳极电容howtheyareappliedinelectronicindustry.精品资料2）Features:Highvoltage,smallcollectoroutputcapacitance.特点:耐压高,集电极输出电容小。3）Arethereanyprecautionswhenadjustingthecapacitancevalue?调整电容值时有哪些注意事项?4）Theformulaofcapacitanceandvoltagedependenceofpowerhasbeeneduced.推导(tuīdǎo)出了功率随电容和电压变化的计算公式。精品资料2．dimensionn.维；尺寸；容积vt.标出尺寸adj.规格的1)relatedphrases：angulardimension角度标注；角度大小(dàxiǎo)lineardimension线性尺寸verticaldimension垂直尺度fitdimension配合尺寸underdimension尺寸过小dimensionscale标注比例精品资料2）Lengthisonedimension,andwidthisanother.长是一种度量，宽又是一种度量。3)Theproblemofthevehiclevelocitydetectionisresolvedbyonedimensionvideotracing.通过一维视频跟踪的方式，解决了车辆速度检测的难题(nántí)。4)Thefinancialdimensiontomarkethigh-qualityproducts,qualityservicetowincustomers.维融以优质的产品占领市场，以优质的服务赢得了客户。精品资料3.volumen.体积；卷；音量；大量；adj.大量的vt.把…收集成卷1)relatedphrases：volumelabel卷标号boundvolume合订本volumecontrol播放控制台volumefraction体积分率；容积比criticalvolume临界(línjiè)容积strokevolume冲程容积；心搏量精品资料2）Theprogressschedulecompiledonthebasisofvolumeproduction.根据批量产品生产预定时间表编制的进度计划；3）Largevolumeofdataweregathered.人们收集了大量的资料。4）Webuyinvolumeandcontractearlytogetthebestprices.大宗采购和尽早(jìnzǎo)签订合同以获得最低货源价格。精品资料4．accumulate[ə'kju:mjuleit]vi.累积；积聚vt.积攒1)relatedphrases：accumulateexperience获取经验(jīngyàn)accumulatepoints积分accumulatepick多重选择accumulatefunds积累资金accumulatedose总剂量，累计剂量精品资料2)WhenweaccumulatemoreandmoresuchdifferencesbetweenChineseandEnglishconsciously,wewillthinkinEnglishwhenwespeakEnglish.当我们有意识地积累了越来越多的类似的英汉差异之时，我们就开始用英语思维来表达事物了。3）Overall,therefore,thecountrydidnotaccumulatesubstantialforeigncurrencyreserves.因此，总体来看，中国没有积累很大的外汇储备(wàihuìchǔbèi)。4）Accumulateandsummarizeallkindsofindexcompleted.Dothebasicandpreparationjoboffinancialbudget.积累总结各项指标完成情况的资料，做好财务预算的基础准备工作。精品资料5．intensity[in'tensəti]n.强烈(qiánɡliè)；强度；亮度；紧张；集中程度1)relatedphrases：fieldintensity磁场强度earthquakeintensity地震强度radiantintensity发光度,辐射率,辐射强度loadingintensity荷载强度intensityofmarketposition市场地位的集中程度精品资料2)Compact,highmagneticinductionintensityandlongcoilservicelife.结构紧凑，磁感应强度高，线圈使用寿命长。3)Thisreducesthelaborintensity,reducepollution,conservewaterresources.这就降低了劳动强度、减少(jiǎnshǎo)污染、节约水资源。4)Compact,highmagneticinductionintensityandlongcoilservicelife.结构紧凑，磁感应强度高，线圈使用寿命长。精品资料6.induced[in‘dju:st]adj.感应的；v.引诱；说服（induce的过去分词)1)relatedphrases：inducedcircuit感应电路；inducedcurrent感生/应电流；inducedradiation感应(生)放射性；inducedfailure诱发故障；inducedoperation诱导(yòudǎo)运算精品资料2）Nauseaanddizzinessinducedbymotion,asintravelbyaircraft,car,orship.晕船（车）：由运动引起的恶心和眩晕，如乘飞机、小汽车或轮船(lúnchuán)。3）Theroadtrafficaccidentsinducedbyfatiguedrivingwillleadtoseverepersonalcasualtyandpropertyloss.疲劳驾驶引发的道路交通事故导致了严重的人身伤亡和财产损失。精品资料7．ironcore：铁芯magneticcore：磁芯core[kɔ:]n.果心,核心,要点vt.挖去(水果(shuǐguǒ)的)果心1)relatedphrases：cablecore电缆芯线；电缆心corediameter芯样直径；根径corepin心型梢；中心销corecompetence/competenc核心能力；关键才能精品资料2）Theearthhaveacoreandamantlearoundit.地球的中心是地核，地核的周围是地幔。3）Teamspiritisthecoreofenterpriseculture.团队精神，是企业文化的核心。4）Themonopolypricingpoweristhecoremeaning.垄断(lǒngduàn)最核心的意义就是定价权。5）Atthecoreofcompetitiveness,likehowtoattractnewcompetitiveness.在核心竞争力不足的时候，就想怎么吸引新的竞争力。精品资料1.Thiscurrentisdependentonthevoltageofthebattery,onthedimensionsofthesample，andontheconductivityofthematerialitself.流过材料的电流取决于电池的电压(diànyā)、材料的截面积和材料自身的电阻率。句中bedependent(on)：“由……决定，取决于”，又如：1)Seatingloadandtightnessisdependentonbackpressure.阀座密封负载和紧密性与反压力相关。精品资料2)Tourismisaresourceandtheenvironmentisheavilydependentontheindustry.旅游业是一个对资源和环境严重依赖的行业。3)Mayyoufindenoughinnerstrengthtodetermineyourownworthbyyourself,andnotbedependentonanother’sjudgmentsofyouraccomplishments.愿你能充分发掘自身潜能，以决定你的价值(jiàzhí)所在，不要让别人的评判埋了你的成绩。精品资料2.bedefinedas：“被定义为”，后接宾语，或“that”引导的宾语从句。如：1）Oneohmisdefinedasthatamountofresistancethatwilllimitthecurrentinaconductorisoneamperewhenthevoltageappliedtotheconductorisonevolt.l欧姆的定义为：当加到导体上的电压为l伏特时，将导体中的电流限制在1安培所需要的电阻值。句中第一个that作定语(dìngyǔ)，第二个that引导定语(dìngyǔ)从句，该从句本身包含了一个when引导的时时间状语从句。精品资料2）Amoleculemaybedefinedasthesmallestparticleofmatterthatcanexistwithoutchangingitsnature.分子可以被定义为物质在不改变其性质的情况下而能存在的物质的最小粒子。3)Motionmaybedefinedasacontinuouschangeofabodyinpositionwithrespecttosomeotherbodyorbodiesatrest.运动可定义为一个物体(wùtǐ)相对于另一个或几个静止物体(wùtǐ)在位置上的连续变化。精品资料3.Capacitorsconsistoftwometalplatesthatareseparatedbyallinsulatingmaterial.电容器是由被绝缘材料分开的两个金属板组成。句中that引导定语从句，修饰twometalplates，consistof表示“由……组成”，又如：1）Auditrisksconsistofintrinsicrisk,controlriskandexaminationrisk.审计风险由固有风险、控制风险和检查风险构成。2）Modernwindfarmsconsistofturbinesthatgenerateelectricity.现代风力(fēnglì)农场由发电的涡轮机组成。精品资料4.Ifthebatteryisdisconnected，thecapacitorretainsthechargeandthevoltageassociatedwithit.如果断开电池，电容器将保持电荷(diànhè)以及与电荷(diànhè)相关的电压。句中retain表示“保持；雇；记住”的意思。又如：1）Helpyourskinretainmoisture.帮助皮肤保持水分。2）Retainyouroriginalreceiptasproofofpurchase.请保留您的原始发票作为购买证明。3）Moneyhastwofunctions,oneistoretainthevalueofwealth,theotherisanexchangevalueofthewealth.金钱有两个职能，一个是保留财富价值，一个是交换财富价值。精品资料5.Thecapacitanceisdirectlyproportionaltothedielectricconstantofthematerialandtotheareaoftheplatesandinverselytothedistanceoftheplates.电容器的电容量与介质的介电常数(jièdiànchánɡshù)及平板的面积成正比,与平板间的距离成反比。a）bedirectlyproportionalto：“与……成正比”b）beinverselyproportionalto：“与……成反比”又如：1)Theresistanceofathinfilm/coatingisdirectlyproportionaltotheresistivity,andinverselyproportionaltothethickness.薄膜镀膜的电阻与该镀镆的电阻系数成正比,与厚度成反比.精品资料2)Themagnitudeoftheforceisfoundtobeinverselyproportionaltothedistancebetweentheconductors.人们发现力的大小与施力者之间的距离成反比。6.Whenacurrentpassesthroughthecoil，amagneticfieldissetuparounditthattendstoopposerapidchangesincurrentintensity．当电流通过线圈时，在线圈周围将产生磁场，它将对抗电流的快速变化(biànhuà)。句中that引导定语从句，修饰amagneticfield，it指代thecoil。opposevt..vi.表示“反对；对抗，抗争”，又如：精品资料1）Smallbanksandsomestateofficialsstronglyopposetheplan.小银行以及某些(mǒuxiē)州的官员强烈反对该方案。2）Weopposeallformsofhegemonismandpowerpolitics.反对各种形式的霸权主义和强权政治。精品资料7.Alsoifacoilisplacedonanironcoreitsinductancewillbegreaterthanitwaswithoutthemagneticcore.而且，如果线圈中放一个铁芯，它的电感将比没有(méiyǒu)铁芯的线圈的电感大。句中than引导一个比较状语从句。inductance[in‘dʌktəns]n.“感应系数；自感应；电感”，又如：1）DCvoltageisdeterminedbyACvoltage,inductanceontheACside,andload.直流侧直流电压是由交流电压、电感及负载决定的。精品资料2）TheeffectsofinductanceandcapacitancemakeitnecessarytocarefullydesignallACtransmissionsystems.电感和电容的影响，使人们必须精心地设计所有的交流输电系统。8.Acoilhasaninductanceofonehenryifaninducedemfofonevoltisinducedinthecoilwhenthecurrentthroughitchangesattherateofoneamperepersecond.当流过线圈的电流以每秒1安培的速度变化时，如果线圈中感应出1伏特感应电动势，那么，线圈的电感就是1亨利。attherateof“以……的速度/速率(sùlǜ)/比率/变化率/频率”又如：精品资料1）Incomefrompropertytransactionsshallbefiledandtaxedattherateof35%.财产交易所得按35%扣缴率申报(shēnbào)纳税。 2）Profitsfromoccasionaltradeshallbefiledandtaxedattherateof30%.一时贸易的盈余按30%扣缴率申报(shēnbào)纳税。精品资料I.Answerthefollowingquestionsaccordingtothetext.

1.Whatiscalledaresistor?Whatistheunitofresistance?

2.Whatistheusageofvariableresistors?Theresistorsaremadefromcarbonmixtures,metalfilms,orresistancewireandhavetwoconnectingwiresattached.The

oppositiontocurrentiscalledelectricalresistance.Variableresistors,withanadjustableslidingcontactarm,areoftenusedtocontrolvolumeonradiosandtelevisionsets.keykey精品资料3.Whatiscalledacondenser?Whichelementsdocondensersconsistof?4.Howtodefineonefaradofthecapacitance?

Thedevicecapableofdoingthisiscalledacapacitororacondenser.Capacitorsconsistoftwometalplatesthatareseparatedbyallinsulatingmaterial.Whenachangerofonevoltpersecondacrossitcausesthecurrentofoneamperetoflow,thecondenserissaidtohavethecapacitanceofonefarad.keykey精品资料5.Whatareinductorsmadeupof?Howtodefineonehenryofaninductance?

Inductorsconsistofaconductingwirewoundintotheformofacoil.Acoilhasaninductanceofonehenryifaninducedemf

ofonevoltisinducedinthecoilwhenthecurrentthroughitchangesatthe

rateofoneampereparsecond.key精品资料II．Fillinthemissingwordsaccordingtothetext．

1.Thiscurrentdependsonthevoltageofthebattery,onthe____ofthesample,andonthe_________ofthematerialitself.A_____isadevicedesignedtohavecapacitance.3.Ohmisusedasaunitof__________.dimensionsconductivitycapacitorresistancekeykeykey精品资料4.Thelargeristheemf,themore___thecapacitorstores．5.Whenachangerofonevoltpersecondacrossitcausesthecurrentofoneamperetoflow,the___issaidtohavethecapacitanceofone_____.6.The___aremadefromcarbonmixtures，metalfilms，orresistancewireandhavetwo______wiresattached.capacitancecondenserfaradresistorsconnectingkeykeykey精品资料1.可变电阻器常用来控制(kòngzhì)收音机和电视机的音量。

2.电容器存储电能的能力叫电容。Unit14Resistor,CapacitorandInductorVariableresistorsareoftenusedtocontrolvolumeonradiosandtelevisionsets.Theabilityofacapacitortostoreelectricalenergyistermedcapacitance.

III．TranslatethefollowingsentencesintoEnglish．keykey精品资料3.任何(rènhé)电感都是由线圈组成，线圈的匝数越多，电感越大。4.电容器的电容量与介质的介电常数及平板的面积成正比,与平板间的距离成反比。Inductorsconsistofaconductingwirewoundintotheformofacoil.Acoilofmanyturnswillhavemoreinductancethanoneoffewturns.Thecapacitanceisdirectlyproportionaltothedielectricconstantofthematerialandtotheareaoftheplatesandinverselytothedistanceoftheplates.keykey精品资料And引导的句型的译法And作连词，用来连接词、短语和句子，其基本意义相当于汉语的“和”、“与”、“并且”。但在实际翻译的过程中，特别是在连接两个句子时，它的译法很多，表达的意义可能相差甚远。如果不考虑and前后成分之间的逻辑关系，只用几种基本译法生硬套用，难免造成理解上的失误，甚至把整个句子意思搞错。l.And表示(biǎoshì)原因，例如：Laseriswidelyusedfordevelopingmanynewkindsofweapons,anditpenetratesalmosteverything.激光广泛用于制造各种新式武器，因为为它的穿透力很强。精品资料2.And表示因果，譬如：1）Butsinceadigitalsignalismadeupofastringofsimplepulses,noisestandsoutandeasilyremoved.但由于(yóuyú)数字信号由一组简单脉冲组成，杂音明显，容易发现，因而容易排除。2）Inl945anewtypeofaeroplaneenginewasinvented,itwasmuchlighterandpowerfulthanearlierengines,andenabledwarplanestoflyfasterandhigherthanever.1945年发明了一种新型的飞机发动机。它比早期发动机要轻的多，功率也要大得多，因此采用这种发动机的军用飞机比以往任何时候都飞得更快、更高。精品资料3.And表示目的，例如：Itwaslatershownthattheresultsofthisworkwerebynomeanstheultimate，andfurtherworkhasbeenputinhandandtoprovideclosercontrolandmoreconsistentoperationinthisarea.后来发现，这项研究工作的结果绝非已作定论，而进一步的研究工作已开始，以便在这方面提供较严密的控制和较稳定的操作。4.And表示承接，譬如：Inmanyways,computerismoresuperiorthanhumanbrain,andhumancanruleit.在许多方面计算机超过人脑，而人却可以控制它。5.And表示对照，例如：例:Motionisabsolute,andstagnationisrelative.运动(yùndòng)是绝对的，而静止是相对的。精品资料6.And表示递进，譬如：例:Theelectronicbraincalculatesathousandtimesquicker,andmoreaccuratelythanispossibleforthehumanbeing.电脑的运算(yùnsuàn)速度比人所能达到的要快1000倍，甚至更加准确。7.And表示转折，例如：例:Therewillalwaysbesomethingsthatarewrong,andthatisnothingtobeafraidof.错误的东西在所难免，但并不可怕。精品资料8.And表示条件，譬如：Evenifaprogrammerhadendlesspatience,knowledgeandforesight,storingeveryrelevantdetailinacomputer,themachine’sinformationwouldbeuseless,andtheprogrammerknewlittlehowtoinstructitinwhathumanbeingsrefertoascommonsensereasoning.即使一个编程员很有耐心、知识和远见，把每一个有关细节都存入计算机，如果他不懂得按人类常识推理去对计算机下达指令，机器里的信息也还是没有用途的。9.And表示结果(jiēguǒ)，例如：Operatorsfoundthatthewaterlevelwastoolowsotheyturnedontwoadditionalmaincoolantpumps,andtoomuchcoldwaterflowingintothesystemcausedthesteamtocondense,furtherdestabilizingthereactor.操作人员发现冷却水的水位过低，就启动了另外两台主冷却泵，结果(jiēguǒ)过量的冷却水进入系统使蒸气冷凝，反应堆因而更不稳定。精品资料TestingandMeasuringInstrumentsAnalogMultimeter

DigitalMultimeter

Bench-typeDigitalMultimeter

DigitalStorageOscilloscope精品资料TestingandMeasuringInstruments

Onceaparticularcomponentissuspectedofbeingfaulty,individualtestsmustbethenperformed.Andthetestingandmeasuringinstrumentsoftentobeusedareasfollow:MultimeterAmultimeterissometimescalledavolt-ohm—milliammeter.Multimetershavingonlyvoltandohmrangesarealsocalledvolt-ohmmeters.Therearetwomainkindsofmultimeters.Theyaremechanicalhandymultimetersanddigitalones.It’sbetterforlearnerstousehandytypes,becauseit’shelpfulforthemtobefamiliarwithsomeelectronicprinciples.

测试仪器一旦怀疑某个(mǒuɡè)元件出故障，就得单独做些测试。常用的测试与测量仪器如下：万用表万用表有时候被称为伏特-欧姆-毫安表。只具有电压(伏特)和电阻档(欧姆)的万用表也叫伏欧表。万用表主要有两种：机械指针式万用表和数字式万用表。初学者最好使用指针式，因为指针式万用表有助于他们熟悉一些电子原理。精品资料

Usingamultimeter，youshouldfirstplaceitflatonatableandnoteifthemeterpointerindicatesexactly0attheextremeleftendoftheblackscale.[1]Ifitdoesn’tread0,turnthescrewonthemetermovementslowlyuntiltheproper0readingisrealized.[2]Andthenconnecttest-1eadtotheother．SettheRANGEswitchtotheproperitemandrange．Insertthetest-leadplugsintothecorrectpairofjacks，cliporholdthetestprobesontheterminalsofthepartbeingchecked，andreadthemeter．使用万用表时，首先你要将万用表平放在桌子上，检查表针是否指向表盘最左端底部黑色分度的零位。如没指到零位(如有偏离)，可慢慢转动万用表上的螺钉(调整(tiáozhěng)旋钮)直到(指针)归零。然后将测试引线连接起来。将“量程”旋钮调至适当的项目和量程上。将表笔插到正确的插孔内，使表笔夹紧被检测部件的末端，然后再读出表上的读数。精品资料

Withamultimeter,wecanmeasurecurrent,voltage,resistance,etc.Andwecanalsotroubleshootappliances,testfuses,measurevoltageatawalloutlet,checkthewiresfromyourroofantenna,findoutwhetherawallswitchisbroken,andperformdozensofotherhouseholdjobs.[3]Introubleshooting,voltagecanbemeasuredwhilethesetison,andresistancecanbemeasuredwhilethesetisoff.Yougetcluestothelocationofthetroublebycomparingyourmultimeterreadingswiththenormalvaluesgiveninservicemanuals.万用表可以用来(yònɡlái)测量电流、电压、电阻等，也可以检测各种装置的电器故障，比如：检测熔丝，测量墙上插座的电压值，检测房顶上的天线，查明墙上的开关是否有了毛病，并完成许多其他，家用电器的检修工作。检测故障时，在被检测设备通电的情况下，可以测量电压而在测量电阻时却要切断被检测设备的电源。将万用表上读数值与使用手册说明上所标定的额定数值对比一下，你就可以得到故障所在位置的线索。精品资料

OscilloscopeOscilloscopeisadisplayinstrument.Withityoucanstudythewave-formofanelectricsignal,suchasthewave-formofalternatingcurrentandvoltage.Youcanmeasurevoltage,current,power,andfrequencyaswell；infact,almostanyquantitythatinvolvesamplitudeandwaveform.示波器示波器是一种显示仪器。你可以用它来研究电信号(例如交流电流和电压)的波形。它也可用来测量电压、电流、功率和频率；实际上，它几乎可以测量涉及(shèjí)到振幅和波形的任何一种量。精品资料

Theheartoftheoscilloscopeisthecathode-raytube(CRT).Thisconsistsofthebase,neck(anelectrongunisincluded),bulbandtheface-plate(screen).Theelectrongunconsistsofacathode,acontrolgrid,ananodeandtwosetsofdeflectionplates.Whenthecathodeisheated,itemitselectrons,whichformelectronbeam.Theelectronbeamsweepsrapidlyfromlefttorightacrossthescreenofacathode-raytube.However,recentlymostofthecathode-raytubesusedinoscilloscopeshavebeenreplacedbyLCDs(LiquidCrystalDisplays),whichgreatlydecreasetheweightandsizeoftheinstrument.示波器的心脏是阴极射线管(CRT)。它由管座、管颈(电子枪在内)、灯泡和面板(显示屏)构成。而电子枪由阴极、控制栅、阳极和两套偏转板构成。阴极受热时发射电子，形成电子束。电子束快速从左至右扫过阴极射线管的荧光屏。然而，近来大多数用于示波器的阴极射线管已经(yǐjing)由LCDs(液晶显示器)取代，液晶显示器大大地减轻了仪器的重量、缩小了仪器的体积。精品资料multimeter[ml'timitə]n.[电]万用表milliammeter[,mili'æmitə]n.[电]毫安计pointer['pintə]n.指针；暗示；scale[skeil]n.刻度；比例；天平vi.攀登；衡量vt.测量；依比例决screw[skru:]vt.vi.转动；旋，拧；压榨；强迫n.螺丝钉；吝啬鬼insert[in'sə:t,'insə:t]vt.插入；嵌入；插入物lead[li:d]n.铅；导线；引线vt.vi.导致；领导adj.带头的；最重要的plug[plɡ]n.栓；插头；塞子vi.塞住；用插头将与电源接通jack[dʒæk]n.千斤顶；插座；插孔vt.提醒；用千斤顶顶起某物(mǒuwù)clip[klip]vt.修剪；夹牢；痛打vi.修剪n.夹子；修剪；回形针精品资料troubleshoot['trblu:t]vt.检修，排除故障vi.充当故障检修员appliance[ə'plaiəns]n.器具；器械；装置设备；应用(yìngyòng)fuse[fju:z]vi.熔化，熔融；融合vt.使熔化n.保险丝；导火线；熔丝oscilloscope['siləuskəup,ə-]n.[电子]示波器；示波镜cathode['kæθəud]n.阴极grid[ɡrid]n.[计]网格；格子，栅格；输电网anode['ænəud]n.[电]阳极，正极deflection[di'flekən]n.偏向；偏差；挠曲crystal[‘kristəl]n.水晶；晶体adj.水晶的；透明的，清澈的精品资料handymultimeter指针式万用表cathode-raytube(CRT)阴极射线管electrongun电子枪controlgrid控制(kòngzhì)栅(极)electronbeam电子束liquidcrystaldisplay(LCD)液晶显示器精品资料

I．Choosethebestanswertocompletethefollowingstatements.

1.Accordingtothetext，_____isthemostcommontoolinrepairingwork．

A．oscilloscopeB．multimeterC．screwD．electrongun2．Themultimetermustbeputhorizontallyandthepointermustpointto_____A．theleftB