Lecture 2 Electronic Instrument Introduction 第二课 电子仪器介绍

Exercises Please read the text and complete the exercises in 30 minutes. 1.Answer the following questions according to the text. What is the main functions of the electronic instruments? ——The leading purpose is to measure various physical quantities such as current, voltage, resistance, temperature, sound level, pressure, etc. What are the advantages and disadvantages of using oscilloscope for voltage measurement? ——The most obvious advantage is that the oscilloscope shows waveform, frequency and phase simultaneously with the amplitude of the voltage being measured.

——The disadvantage is the problem of resolution. How do you determine the RMS of voltage using the oscilloscope? ——Peak to peak value divided by 2. What can a multi-meter measure? ——It can measure DC and AC voltage, current, resistance, and in some cases, decibels. Which three types of waveforms can the EE1641B Model function signal generator produce? ——Sine, square and triangle.

2.Translate the following phrases and expressions. present an accurate electronic picture —— 显示精确的波形 be calibrated in relation to sine waves —— 根据正弦波来校准 to contain significant harmonics —— 含有大量谐波 to interpolate between divisions —— 细分刻度

peak-to-peak value —— 峰 - 峰值 be in series with the circuit or component to be measured —— 与测量的电路或元件串联

3.Choose the best answer. The best source of information about an instrument is the operating and instructions manual, which is provided with any new instrument purchased. Here the underlined word “which” means _____. A. best source of information B. an instrument C. the operating and instructions manual If you are not thoroughly familiar _____ an instrument’s operation, read the manual before using the instrument. A. with B. about C. to C A

“The most obvious advantage is that the oscilloscope shows waveform, frequency and phase simultaneously with the amplitude of the voltage ( or current) being measured.” Here the underlined part is used as ______. A. 宾语 B. 形式主语 C. 表语 When the signals being measure contain significant harmonics, the calibrations are inaccurate. The word “significant” can be replaced by ______. A. important B. a large amount of C. difficult C B

We can measure DC and AC voltage, current, resistance ______ a multi-meter. A. with B. by C. from When measuring current, the circuit must be _____ and the meter inserted in ______ with the circuit or component to be measured. A. short…series B. opened…parallel C. opened…series B C

4.Judge true or false according to the text. We can use an oscilloscope to show the RMS of voltages directly. ( ) It has a low resolution using oscilloscope to measure voltage. ( ) The scales of simple VOMs are more difficult to read in comparison with an oscilloscope. ( ) It is obvious that the oscilloscope can show waveform, frequency, phase and also the amplitude of the voltage being measured. ( ) A voltmeter is always placed in series with the circuit or component to be measured. ( ) F F F T T

5.Translate the following sentences into English. 电子仪表可用于测量各种各样的物理量，如电流 、电压、电阻、温度等。 ——The electronic instruments can be used to measure various physical quantities such as current, voltage, resistance, temperature, etc. 示波器在测量电路中的电压和电流时既有优点也 有缺点。 ——Oscilloscope has both advantages and disadvantages when used to measure voltage or current in a circuit.

电压表需并联于待测量的电路或元件两端。 ——A voltmeter must be placed in parallel with the circuit or component to be measured. 如果感兴趣的只是电压或电流的大小，可直接使 用万用表测量。 ——If the only value of the interest is voltage or current amplitude, use the voltmeter directly.

Key words and Technical terms quantity 量，数量 ——physical quantities current 电流 voltage 电压 resistance 电阻 sound level 音量 pressure 压力，电压 delicate 精密的 ——delicate devices sensitive 敏感的，灵敏的 ——sensitive devices

instruction 指示，说明书，指令 manual 手册，指南 ——operating manual specification 详述，规格，规范 limitation 限制，局限性 oscilloscope 示波器 accurate 正确的，精确的 ——accurate electronic picture amplitude 幅度 frequency 频率 phase 相位

VOM 电子伏特表 voltmeter 伏特计 ——electronic voltmeter meter 电表 calibrate 校准 sine 正弦 ——sine waves significant 有意义的，重要的，大量的 harmonic 谐波 ——harmonic content resolution 分辨率

scale 进制，刻度 vertical 垂直的 ——vertical scale division 分开，分割 ——each scale division interpolate 插入 ——interpolate between divisions peak-to-peak value 峰 - 峰值 RMS (root-mean-square) 均方根值（有效值） maintenance 保持，维护，维修 troubleshooting manuals 故障手册

readout 读数 wave shape characteristics 波形特性 multi-meter 万用表 general-purpose 通用 ——general-purpose meter decibel 分贝 numerical 数字的 ——numerical display jack 插孔，插座 ——positive jack, common jack

test leads 测试引线 function switch 功能开关 range switch 量程开关 polarity 极性 facilitate 使容易，使便利 adjust to zero 调零 a zero adjust control 调零控制 compensate 偿还，补偿 ——compensate for battery 电池 ——weakening battery

indicator 指示器 place across 跨接 in series with 与 … 串联 in parallel with 与 … 并联 generator 发电机，发生器 ——function signal generator versatile 通用的，万能的 ——versatile signal source triangle 三角形 ——triangle wave waveform sketch map 波形图

attenuation 衰减 ——attenuation button counter 计数器 scanner 扫描仪

Expressions be familiar with… 对 … 熟悉 ——If you are not thoroughly familiar with an instrument’s operation, specifications, functions, and limitations, read the manual before using it. in relation to… 与 … 有关，涉及 ——Most meters are calibrated in relation to sine waves. multiply …by … 用 … 乘 … ——Multiplying 2 by 3 makes 6. be converted to … 把 … 转换成 ——Usually the peak-to-peak value is required to be converted to RMS.

be capable of 能够 ——A multi-meter is a general-purpose meter capable of measuring DC and AC voltage, current and resistance. in parallel with … 与 … 并联 ——When measuring the resistance of a component in a circuit, the voltage to the circuit must be removed and the meter placed in parallel with the component. take …as an example 以 … 为例 ——Take the EE1641B Model function signal generator as an example. range from …to … 从 … 到 … 的范围 ——The wide frequency of the signal generator ranges from 0.2Hz to 2MHz.

Core Sentences Translation The best source of information about an instrument is the operating and instructions manual, which is provided with any new instrument purchased. —— 有关仪器的最佳信息来源是操作手册和说明书， 购买的新仪器都会附带。 The most obvious advantage is that the oscilloscope shows waveforms, frequency and phase simultaneously with the amplitude of the voltage being measured. —— 最明显的优点是示波器在测量电压幅度时，能同 时显示波形、频率和相位。

With the oscilloscope, the voltage is measured from the displayed wave, which includes many harmonic content. —— 用示波器（测量），电压是根据显示的含有许 多谐波分量的波形测得的。 In most cases, the oscilloscope’s vertical scales are used for voltage (or current) measurements, with each scale division representing a given value of voltage (or current). —— 大多数情况下，示波器的垂直刻度用于测量电 压（或电流），每一小刻度代表一定的电压值（ 或电流值）。

The amplitude of a voltage waveform on an oscilloscope screen can be determined by counting the number of centimeters, vertically, from one peak to the other peak of the waveform and multiplying it by the setting of the volts/cm control. —— 示波器屏幕上的电压波形的幅度可以通过波形 峰 - 峰值所占的垂直厘米数（格数）乘上控制旋钮 所设定的伏特 / 厘米来确定。 To sum up, if the only value of interest is voltage amplitude, use the meter because of its simplicity in readout. —— 总而言之，如果只想知道电压幅度，就使用电 压表，因为它读数简便。

There are two types of multi-meters: analog, using a standard meter movement with a needle, and digital, with an electronic numerical display. —— 有两种类型的万用表：使用标准仪表指针的模拟 式万用表和使用电子数字显示的数字式万用表。 The needle will have a screw for mechanical adjust to set it to zero and also a zero adjust control to compensate for weakening batteries when measuring resistance. —— （有一个）螺丝钉用于机械调零（万用表）指针 ，且可在测量电阻时通过调零控制补偿电池损耗。

A voltmeter is always placed across the circuit or component to be measured. —— 电压表总是跨接于待测的电路或元件两端。 When measuring current, the circuit must be opened and the meter inserted in series with the circuit or component to be measured. —— 当测量电流时，电路应当断开并将仪表插入， 与待测量的电路或元件串联。

This model of signal generator provides the following types of waveform for output: sine, square and triangle. —— 这种型号的信号发生器可提供如下输出波形： 正弦波、方波、三角波。 You should choose the proper “frequency range” button and adjust the “amplitude” knob to obtain the signal you want from the “50Ω” output terminal. —— 应选择合适的 “ 频率范围 ” 按钮及调节 “ 幅度 ” 旋钮 从而在 “50 欧 ” 输出端获得所需信号。