Electrical Indicating and Test Instruments 1 Introduction 161

Problems

1. 
   Summarize the advantages of digital meters over their analogue counterparts.
   
2. 
   Explain the four main alternative mechanisms used for affecting analogue-to-digital conversion in a digital voltmeter.
   
3. 
   What sort of applications are analogue meters still commonly found in?
   
4. 
   Explain the mode of operation of a moving coil meter.
   
5. 
   Explain the mode of operation of a moving iron meter.
   
6. 
   How does an oscilloscope work?
   
7. 
   What are the main differences between analogue and digital oscilloscopes?
   
8. 
   Explain the following terms: (a) bandwidth and (b) rise time. In designing oscilloscopes, what relationship is sort between bandwidth and rise time?
   
9. 
   Explain the following terms in relation to an oscilloscope: (a) channel, (b) single- ended input, (c) differential input, (d) time base, (e) vertical sensitivity, and (f) display position control.
   
10. 
    Sketch a block diagram showing the main components in a digital storage oscilloscope and explain the mode of operation of the instrument.
    
11. 
    Draw a block diagram showing the main components in a digital phosphor oscilloscope. What advantages does a digital phosphor oscilloscope have over a digital storage one?
    
12. 
    Illustrate the main components in a digital sampling oscilloscope by sketching a block diagram of them. What performance advantages does a digital sampling oscilloscope have over a digital storage one?
    
13. 
    What is a PC-based oscilloscope? Discuss its advantages and disadvantages compared with a digital oscilloscope.
    

What are the main differences among a digital storage oscilloscope, a digital phosphor oscilloscope, and a digital sampling oscilloscope? How do these differences affect their performance and typical usage?