Draper DMM11, Instructions Manual

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OPERATION
WARNINGS:
Before you use the instrument, inspect the test leads, connectors and probes for damage e.g.
cracks or breaks in the insulation. Replace any defective leads before use. If the voltage to be
measured is not known, set the selector switch to the highest range and reduce until a satisfactory
reading is obtained.
DC Voltage Measurement
1. Connect the red test lead to the ‘V/
Ω
/F’ jack socket and the black lead to the ‘COM’
jack socket.
2. Set the selector switch to the desired D.C.V. range (V ... ).
3. Connect the test leads to the circuit to be measured.
4. Turn on the power to the circuit to be measured, the value should appear on the digital display
along with the voltage polarity (if reversed only).
AC Voltage Measurement
1. Connect the red test lead to the ‘V/
Ω
/mA’ jack socket and the black lead to the ‘COM’
jack socket.
2. Set the selector switch to the desired A.C.V. range (V~).
3. Connect the test leads to the circuit to be measured.
4. Turn on the power to the circuit to be measured. The voltage value will appear on the
digital display.
Current Measurement
1. Connect the red test lead to the ‘mA’ or ‘A’ jack socket and the black lead to the ‘COM
jack socket. (For measurements between 200mA and 10A connect the red test lead to the
‘A’ socket. (Max. 20A).
2. Set the selector switch to the desired A.C./D.C. range (µA, mA or A) and push the ‘ .../~’
button.
3. Open the circuit to be measured and connect the test leads IN SERIES with the load
in which current is to be measured. (See Fig. 1).
4. Turn on the power to the circuit to be measured the ‘AMPERAGE’ value should appear on the
digital display.
Resistance Measurement
1. Connect the red test lead to the ‘V/
Ω
/F’ jack socket and the black lead to the ‘COM’
jack socket.
2. Set the selector switch to the OHM position (
Ω
).
3. WARNING: If the resistance to be measured is part of a circuit, turn off the power and
discharge all capacitors before measurement. If the reading is less than 200M
Ω
, the
display will show 1M
Ω
, this figure should be subtracted from measurement results.
4. Connect the test leads to the circuit to be measured.
5. The resistance value should now appear on the digital display.
Diode Measurement
1. Connect the red test lead to the ‘V/
Ω
/F’ jack socket and the black lead to the ‘COM’ jack
socket.
2. Set the selector switch to the position.
3. Connect the red test lead to the anode of the diode to be measured and the black test
lead to the cathode.
4. The forward voltage drop in mV will be displayed. If the diode is reversed, the figure ‘1’
should show on the display.