Measuring Resistance - Ryobi RP4020 Operator's Manual

ALLIGATOR CLIPS
See Figure 5, page 15.
A set of alligator clips is included with the multimeter, one
for the black lead, and another for the red lead. When you
want the meter to remain connected to a circuit, but want
to keep your hands free for other operations, the alligator
clips will hold the leads in place.
To use the clips:
 Make sure the multimeter is turned off.
 Insert the end of the red lead probe into the metal connec-
tion inside the alligator clip cover. Make sure it is securely
connected.
 Repeat the above step with the black lead and black
alligator clip.
 Connect the leads to the circuit using the alligator clips.
NOTE: Do not allow the multimeter to hang by its leads
when the clips are connected to a circuit. Always use the
kick stand or convenience hook, or place the multimeter
on a stable surface.
CAUTION:
To avoid damaging the meter or blowing the fuses, always
remove the test leads from the source or load before
turning the mode selection dial.
MEASURING DC VOLTAGE
See Figure 6, page 15.
NOTE: To avoid electric shock to you or damages to the
meter, do not attempt to measure DC voltage higher than
600V although readings may be obtained.
 Connect the black test lead to the COM jack and the red
test lead to the
 Set the mode selection dial to
 Select autorange mode or manual range mode with the
RANGE button.
If you use manual range mode and don't know the magnitude
of the voltage to be measured beforehand, select the highest
range and then reduce it range by range until satisfactory
resolution is obtained.
 Connect the test leads across the source or load to be
measured.
 Read the display. The polarity of the red lead connection
will be indicated as well.
 Remove the test leads from the source or load before
turning the mode selection dial.
MEASURING AC VOLTAGE
See Figure 7, page 15.
NOTE: To avoid electric shock to you or damages to the
meter, do not attempt to measure AC voltage higher than
600V although readings may be obtained.
 Connect the black test lead to the COM jack and the red
test lead to the
OPERATION
μA/mA
jack.
range.
μA/mA
jack.
11 – English
 Set the mode selection dial to
 Select autorange mode or manual range mode with the
RANGE button.
If you use manual range mode and don't know the magnitude
of the voltage to be measured beforehand, select the highest
range and then reduce it range by range until satisfactory
resolution is obtained.
 Connect the test leads across the source or load to be
measured.
 Read the display.
 Remove the test leads from the source or load before
turning the mode selection dial.
MEASURING DC OR AC CURRENT
See Figure 8, page 15.
NOTE: If the magnitude of the current to be measured is not
known beforehand, select the highest range and then reduce
it range by range until satisfactory resolution is obtained.
 Connect the black test lead to the COM jack. If the cur-
rent to be measured is less than 400mA, connect the red
test lead to the μA / mA jack. If the current is between
400mA and 10A, connect the red test lead to the 10A
jack instead.
 Set the mode selection dial to
 Press the MODE button to select DC or AC current
measurement, the display shows the corresponding
symbol.
 Turn off power to the circuit you will measure. Discharge
all high voltage capacitors.
 Break the circuit path to be measured, then connect the
test leads in series with the circuit.
 Turn on power to the circuit, then read the display. For DC
current measurements, the polarity of the red test lead
connection will be indicated as well.

MEASURING RESISTANCE

See Figure 9, page 15.
NOTE: Before measuring in-circuit resistance, disconnect all
power to the circuit to be tested, and discharge all capaci-
tors fully.
 Connect the black test lead to the COM jack and the red
test lead to the
NOTE: The polarity of the red lead is positive ( + ).
 Set the mode selection dial to
 Connect the test leads across the load to be measured.
 Read the display.
NOTE: For measurements > 1M
a few seconds to stabilize reading. This is normal for high
resistance measurements.
 When the input is not connected, i.e. at open circuit, OL
will be displayed as overrange indication.
range.
,
or position.
μA/mA
jack.
Ω
range.
Ω
, the meter may take