Unit 1. Electrical Test Equipment & Testing Components (SA)
What does the "OL" symbol identify on a digital multimeter?
"OL" means the meter is "Over loaded" or out-of-range.
What should the voltmeter reading be across a good fuse if 120VAC is applied to the circuit? Answers to Self-Test Questions 401 1. Connect the voltmeter in parallel with the load. 2. Connect the ammeter in series with the load. 3. No. The circuit should always be de-energized to avoid damage to the meter. 4. "OL" means the meter is "Over loaded" or out-of-range. 5. A megohmeter. 6. An ammeter. 7. A battery load tester. 402 1. Use an ohmmeter on a de-energized circuit. 2. Replace the device. 3. The capacitor should always be discharged first. 4. The diode is shorted and should be replaced. 5. 0 (zero) VAC. Do the
0 (zero) VAC.
What tool is often used to test the overall condition of a battery?
A battery load tester.
What meter is commonly used to measure the insulating material of an alternator?
A megohmeter.
What meter can be used to check the current value of a circuit without any circuit interruption?
An ammeter.
How is an ammeter connected in relation to the circuit being tested?
Connect the ammeter in series with the load.
How is a voltmeter connected in relation to the circuit being tested (series or parallel)?
Connect the voltmeter in parallel with the load.
Should the circuit be energized when checking for resistance with an ohmmeter?
No. The circuit should always be de-energized to avoid damage to the meter.
What should be done when an "open" is found when testing an inductor?
Replace the device.
In addition to de-energizing the circuit, what other step should be taken before testing a capacitor with an ohmmeter?
The capacitor should always be discharged first.
When testing a diode with an ohmmeter, what is signified by a low resistance value in both directions?
The diode is shorted and should be replaced.
What is the preferred method of checking a circuit for unit of resistance?
Use an ohmmeter on a de-energized circuit.