399 399 CHAPTER OUTLINE 21.1 Electrical Safety 21.1.1 Physical Condition 21.1.2 Electrical Testing Safety 21.1.3 Overvoltage Categories (CAT Level) 21.1.4 Electrical Testing Safety Rules 21.2 Field Testing and Bench Testing 21.3 Electrical Measurement Tools 21.3.1 Test Lights 21.3.2 Continuity Tester 21.3.3 Receptacle Testers 21.3.4 Digital Multimeter (DMM) 21.3.5 Clamp-On Ammeter 21.3.6 Megohmmeter 21.3.7 LCR Meter 21.3.8 Oscilloscopes 21.3.9 Power Supplies 21.3.10 Arbitrary Function Generators 21.3.11 Phase Sequence Tester 21.3.12 Infrared Thermometer 21.4 Calibration LEARNING OBJECTIVES After completing this chapter, you will be able to: □ Discuss test and measurement safety procedures. □ Identify assembly-level and component-level trouble- shooting methods. □ Explain the use of test lights, continuity testers, and receptacle testers. □ Understand the capabilities and uses of a digital multimeter. □ Demonstrate the use of oscilloscope controls and measurement methods. □ Use a clamp-on ammeter. □ Interpret oscilloscope calibration waveforms. □ Explain the use of power supplies and signal generators. □ Discuss the use of a phase sequence tester. □ Understand the need for calibration and the calibration process. TECHNICAL TERMS arbitrary function generator (AFG) auto-ranging clamp-on ammeter continuity tester cursor digital multimeter (DMM) infrared (IR) thermometer International Electrotechnical Commission (IEC) LCR meter megohmmeter noncontact voltage tester oscilloscope overvoltage phantom voltage phase sequence tester receptacle tester screwdriver voltage tester test light triggering Ito t is not possible to see the actual flow of electricity through a circuit—only the effects of it are visible. Electrical test and measurement equipment enables you “look inside the circuit” and visualize what is happening. After taking electri- cal measurements, you can use basic electrical calculations to predict other values in that circuit. See Figure 21-1. In this chapter, you will learn about different types of test equipment and the various measurements each is capable of taking. As you become proficient using measurement equipment and techniques, your troubleshooting abilities will continue to grow. Select the icons to access Drill and Practice activities. ◀ Xmentoys/Shutterstock.com Ch21.indd 399 4/26/2019 1:08:36 PM