TM 5-2420-231-23-3
0370
MULTIMETER USAGE CONTINUED
Measuring AC Voltage
000370
CAUTION
Take care not to damage electrical terminals when probing with test equipment. Terminal
damage will occur when forcing a test probe into an electrical terminal.
Failure to follow this caution may induce additional symptoms and lead to an inaccurate
diagnosis.
Failure to follow these cautions may result in equipment failure.
1. Select VOLTS AC on digital multimeter.
2. Select highest voltage range or a range that is higher than voltage to be measured.
3. Connect red probe to circuit being tested, and connect black probe to low reference circuit, ground circuit, or
machine ground as directed in Troubleshooting. If a negative voltage is measured, reverse multimeter probes
at test points.
4. Monitor and record reading. Digital multimeter displays a number representing AC voltage.
Measuring Frequency/Duty Cycle
000370
CAUTION
Take care not to damage electrical terminals when probing with test equipment. Terminal
damage will occur when forcing a test probe into an electrical terminal.
Failure to follow this caution may induce additional symptoms and lead to an inaccurate
diagnosis.
Failure to follow these cautions may result in equipment failure.
1. Select VOLTS AC.
2. Select the frequency function.
3. Connect red probe to circuit being tested, and connect black probe to low reference circuit, ground circuit, or
machine ground as directed in Troubleshooting.
4. Observe readout. Values are represented as percentages.
END OF TASK
AMMETER USAGE
0370
An ammeter is used to measure current values in the electrical system of the machine. The ammeter clamps on a
single wire to obtain a current reading on a circuit.
Test Ammeter
000370
Select highest DC amperage range or a range that is higher than amps to be measured.
Measure Amperage
000370
1. Press the jaw trigger to open the jaw, and place the jaw around the wire or cable being tested.
2. Monitor and record reading. Ammeter displays a number representing current.
END OF TASK
0370-19
