1. What do we use to measure these electrical quantities ?? Revision02 1 Class discussion

2. Measuring circuit parameters Ensure correct polarity Check scale is correct Voltmeters go ACROSS the component 2 Revision02 Using separate meters + -

3. Ammeters Ammeters go IN the circuit Check the correct scale Ensure correct polarity 3 Revision02

4. Measuring the resistance of a component NEVER attempt to measure resistance on a live circuit! 4 Revision02

5. Clip-on ammeter CAUTION live circuit one conductor only check scale check if AC or DC induction meter on AC only 5 Revision02

6. Revision02 6 Meters Typical Clamp Meters Attachment for multimeter

7. 2 basic types moving coil (DC coils on AC use diode for the DC) moving iron (AC & DC) Parallax error Some meters have a mirror scale to reduce reading errors. Revision02 7 Analogue meters

8. Low value resistance measurement eg; () Bridge instruments High Value resistance measurements eg; (M) insulation resistance testers Revision02 8 Continuity and resistance testers

9. Do not measure voltage accurately. Neon indicators need about 90V before they work You have no guarantee that there is zero volts. Revision02 9 Circuit indicators