MEASURING WATTAGE
You can use the multimeter and am- meter to tell how many watts of power an appliance uses. This helps you de- termine what the electricity costs are for that appliance.
The following formula can help you make the necessary conversion.
V (volts) ⋅ A (amps) = W (watts)
To determine how many watts an ap- pliance uses, use your multimeter to measure the number of volts it uses (120 volts
MEASURING
RESISTANCE
The resistance measuring circuit in your multimeter compares the voltage gained through a known resistance (internal) with the voltage developed across an unknown resistance.
WARNING: BE SURE THE CIRCUIT UNDER TEST HAS ALL POWER REMOVED AND ANY ASSOCIATED CAPACITORS ARE FULLY DIS- CHARGED BEFORE YOU MAKE A RESISTANCE MEASUREMENT.
Caution: Never connect the test leads to a source of voltage when the function selector is set to R⋅1KΩ or R⋅100Ω.
Note: When you measure the resis- tance of a component in a circuit, dis- connect one side of the component you are testing. This prevents other components in the circuit from inter- fering with the reading.
Follow these steps to measure resis- tance.
1.Set the function selector to
R⋅1KΩ or R⋅100Ω.
2.Touch the test leads together, then rotate OHMS ADJUST on the side of the multimeter until the needle points to 0 on the top line on the multimeter.
3.Touch the test leads across the circuit you want to measure, or remove one of the leads of the component you want to measure from its circuit and touch the test leads across the component. Then read the top OHMS line on the multimeter.
•If the function selector is set to R⋅100Ω, multiply that reading by 100 to compute the resistance. For example, if the needle points
to 1, the resistance is 100 ohms (1 ⋅ 100 = 100Ω).
16 | Using the Multimeter |
