TM 5-6675-348-13&P
a.
Measurements Required for Troubleshooting.
Use properly sized test leads and ensure care is used when checking for resistance,
continuity, or voltage at connectors, or damage to equipment may result.
(1)
Resistance measurements.
(a)
Connect red test lead to Volt-Ohm input connector and black lead to COM input connector on
meter.
(b)
Set function/range switch to desired Ohm position. If magnitude of resistance is not known,
set switch to highest range, then reduce until satisfactory reading is obtained.
(c)
If resistance being measured is connected to circuit, disconnect power from circuit.
(d)
Connect test leads to circuit being measured. When measuring high resistance, be careful not
to contact adjacent points, even if insulated. Some insulators have relatively low insulation
resistance, which can affect resulting measurement.
(e)
Read resistance value on digital display.
(2)
Continuity checks.
(a)
Place function/range switch in any Ohm range.
NOTE
Some meters show "1+m", or simply "1" when function/range switch is in any Ohm position.
(b)
Connect red test lead to Volt-Ohm input connector and black lead to COM input connector on
meter. When test leads are separated or measuring an out-of-range resistance, digital display
will indicate "OL" (Over Limit).
(c)
Put one test probe at one end of wire or circuit to be tested. Use other test lead to trace circuit.
When continuity is established, Ohm symbol will appear in upper left corner of digital display.
If contact in wire is maintained long enough (about 1/4 second), the OL will disappear and
resistance value of wire or circuit will appear next to symbol.
(d)
If multimeter does not work in this manner, learn how it operates before performing trouble-
shooting.
(3)
Voltage measurements.
(a)
Connect red test lead to Volt-Ohm input connector and black lead to COM input connector on
meter. If DC-AC switch is present, ensure it is set to DC position.
(b)
Set function/range switch to desired voltage position. If magnitude of voltage is not known, set
switch to range which will be able to read most voltages seen on equipment (typically, 200-V
range will do). Reduce range until satisfactory reading is obtained.
