1. ADT490 Metering Techniques

2. 2 Introduction ‣ Alarms ALS390 ‣ Foundation for Troubleshooting

3. 3 Concept Review ‣ Current ‣ Voltage 3

4. 4 Concept Review - Conductors ‣ Conductor resistance is American Wire Gage 4

5. 5 Concept Review - Resistance ‣ Depends Primarily on ‣ Length ‣ Cross-sectional area ‣ Type of Material ‣ Conductors DO have Resistance 5

6. 6 Concept Review - Resistor ‣ Limit Current / Divide Voltage / Convert Energy ‣ Ohms & Watts 6

7. 7 Series DC Circuits ‣ Current same / Voltage divided between Resistors 7

8. 8 Series DC Circuits - Resistance 8

9. 9 Kirchhoffs Voltage Law 9 -

10. 10 Voltage Dividers 10

11. 11 Parallel DC Circuits ‣ Voltage in each parallel branch is equal 11

12. 12 Kirchhoff’s Current Law For each Junction: Current in = Current out 12

13. 13 Resistance in Parallel 13

14. 14 Resistance in Parallel - Rules ‣ R T always < value of smallest resistor ‣ If largest resistor many times smaller resistor ‣ R T approaches value of smallest resistor. ‣ If two resistors equal ‣ R T is half original resistance 14

15. 15 Current Dividers 15

16. 16 AC Voltage & Current 16

17. 17 AC Voltage & Current 17 Text

18. 18 Measuring with a Multimeter 18

19. 19 Using a Voltmeter 19

20. 20 Using a Voltmeter 20

21. 21 Using a Voltmeter ‣ Can use a voltmeter to check a fuse - SAFER 21

22. 22 AC Versus DC ‣ No reading ‣ CHECK METER ‣ Power on circuit 22

23. 23 AC Versus DC 23

24. 24 Using an Ammeter 24

25. 25 Using an Ammeter 25

26. 26 Using an Ammeter ‣ Fuse in circuit - 0 A fuse good, ? A fuse bac ‣ Watch the meter raing 26

27. 27 Measuring Resistance ‣ Voltage impacts on reading - Nonsense Reading ‣ Highest to Lowest - Lowest most accurate 27

28. 28 Ohmmeter Uses ‣ Check if EOL is Capacitor - Short then Charge ‣ Determine device polarity 28

29. 29 End of Presentation