测控技术与仪器专业英语 张凤登UNIT-8.Measuring Technique
UNIT 8 Measuring Technique,8.1 Text Errors in Measurement 测量中的误差,New Words geometric diu'metrik a. 几何的，几何学的 propagate 'prpeit v. 传播，宣传，繁殖 coordinate ku':dinit n. v. 坐标（用复数）；调整，整理 graduated 'rædjueitid a. 分度的 theodolite i'dlait n. 经纬仪 bubble 'bbl n. 气泡，泡 dexterity dek'sterti n. 灵巧，机敏，灵活，熟练 blunder 'blnd n. v. 大错，失误；犯大错，做错 gross rus a. 显著的，严重的，总的，毛的 obviate 'bvieit v. 消除，排除，回避，避免，预防 conscientious ,kni'ens a. 尽责的 algebraic ,ældi'breiik a. 代数的 curvature 'k:vt n. 弯曲，曲率 refraction ri'frækn n. 折光，折射,New Words (continue) trigonometric ,trin'metrik a. 三角法的，据三角法的 calibration ,kæli'brein n. 标度，刻度，校准 unquantifiable ,nkwnti'faibl a. 不可测量的，难以计算的,Notes Also, it is the indirect nature of measurements that forces the need to often apply some rather sophisticated mathematical procedures to analysis of errors and thus determine a “best value” to present the size of the quantity. 而且，测量的间接性要求必须采用一些非常复杂的数学程序来分析误差，这样才能确定出一个表征数值大小的“最佳值”。 gross error 严重错误，过失误差 law of probability 概率论,Exercises 1. Answer the following questions. The sources of errors fall into three broad categories. They are the instrumental error， natural error， and personal error. The natural error is caused by variation in the surrounding environment conditions， whereas Personal Error arises due to limitations in human senses. Yes， it does. From the discussion thus far it can be stated with absolute certainty that all measured values contain errors， whether due to lack of refinement in readings， instabilities in environmental conditions， instrumental imperfection or human limitations. Mistake actually is not an error because it usually is so gross in magnitude compared to the systematic or random errors. Systematic errors follow some physical law and thus can be predicted whereas random errors are introduced into each measurement mainly because of human and instrument imperfections as well as uncertainties in determining the effects of the environment on measurements Systematic errors can be known in advance. The systematic error can be reduced by some correct measurement procedures. Generally， Random errors are unavoidable and relatively small. They usually do not follow any physical law， but follow the laws of “chance”.,Exercises (continue) 2. According to the text, fill in the blanks with suitable words or phrases given below in the correct form. compensate instrumental error deal with reading inattention （1） reading （2） instrumental errors （3） inattention （4） be compensated （5） be dealt with,8.2 Reading and Translation Temperature Instrumentation 测温仪表,New Words deflection di'flekn n. 偏向，偏转，折射 spiral 'spairl n. a. 螺旋；螺旋的，盘旋的 helix 'hi:liks n. 螺旋（形），螺旋线 sheath i: n. 套 pyrometer pai'rmit n. 高温计，高温表 pyrometry pai'rmitri n. 高温测定法，高温测量 thermopile ':mupail n. 热电堆 readout 'ri:daut n. 读数,Notes lend itself to 有助于，适宜于，对有用 direct to 把对准某一目标（或方向）,斜体部分参考译文: If two different kinds of metal strips are bonded together and heated, the resulting strip will bend in the direction of the metal with the lower expansion rate. The amount of resulting deflection that occurs is proportional to the square of the length and the total change in temperature, and is inversely related to material thickness. 如果两种不同的金属条粘合在一起，并被加热，得到的金属条将产生弯曲，弯曲的方向与膨胀率较低的金属相同。产生的偏转量与长度的平方和温度的总变化成正比，与材料厚度成反比。 In practice, this includes resistance changes, voltage generation, radiation, and optical comparisons. The sensing element or transducer of these instruments must have the ability to distinguish between temperature changes and judge the amount of heat in an object. 在实践中，其中包括电阻变化、电压生成、辐射和光对比（optical comparisons）。这些仪表的传感元件或转换器必须有能力区分温度变化，判断物体的热量。 The sensor of a thermoresistant instrument is simply a long piece of wire formed into the shape of a coil wound around a ceramic core. The entire assembly is then enclosed in a protective sheath. Connection to the wire coil is made by passing leads through the ceramic core, forming a stress relief junction. 热阻式仪表的传感器仅仅是一根绕在陶瓷芯上的线圈形长金属线线。然后，整个组件被封装在一个保护性护套中。线圈的连接由穿过陶瓷心的引线实现，由此形成的连接点能够起到应力缓和作用。,斜体部分参考译文(续): Thermocouple temperature indicators respond to the electrical property that when two dissimilar metals are heated at a common connection point, a dc voltage is generated. The resulting voltage measured across the free ends of the thermocouple wires can be used to indicate temperature applied to the measuring junction. 当两种不同金属的公共结点被加热，就会生成一个直流电压，热电偶温度指示器对电气特性做出响应。通过测量热电偶自由端所产生的电压，可以用来显示作用于测量结点的温度。 This component, being a solid-state device, differs from its RTD counterpart by having a negative temperature coefficient of resistance. As a result, increases in temperature cause a corresponding decrease in resistance. 这个元件是固态的，不同于与之对应的RTD测温元件，热敏电阻的电阻温度系数为负值，其结果是温度增加导致电阻相应地减少。 A special type of optical system is employed that collects visible and infrared energy and focuses it on a detector element. The detector then change
