Maplin N73CG Assembly instructions

OPERATOR’S
INSTRUCTION MANUAL
N73CG
MINI DIGITAL MULTIMETER

1
G ENERAL
The N73CG a is compact, pocket-sized 3½ digit multimeter for
measuring DC and AC voltage, DC current, resistance, diode function,
temperature, transistor function and includes an audible continuity test
function. Full range overload protection and low battery voltage indication
are provided. It is the ideal instrument for use in the laboratory, the
workshop and for hobby and home applications.
FRONT PANEL DESCRIPTION
1. FUNCTION AND RANGE SWITCH
This switch is used to select the function and desired range as well
as to turn on the instrument.
To extend the life of this battery, the switch should be in the "OFF"
position when the instrument is not in use.
2. DISPLAY
3½ digit, 7 segment, 0.5" high LCD.
3. "Common" SOCKET
Plug in connector for black (negative) test lead.
4. "V Ω mA" SOCKET
Plug in connector for red (positive) test lead for all voltage,
resistance and current (except 10A) measurements.
5. "10A" SOCKET
Plug in connector for red (positive) test lead for 10A current
measurement.
SPECIFICATIONS
Accuracies are guaranteed for 1 year
(storage conditions: 23 ℃± 5 ℃ , less than 75% RH).
DC VOLTAGE
RANGE RESOLUTION ACCURACY
200mV 100 μ V ± 0.5% of rdg ± 2D
2000mV 1mV
± 0.5% of rdg ± 2D
20V 10mV ± 0.5% of rdg ± 2D
200V 100mV ± 0.5% of rdg ± 2D
600V 1V ± 0.8% of rdg ± 2D

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OVERLOAD PROTECTION: 220V rms AC for 200mV range and 600V
DC or 600V rms AC for other ranges.
AC VOLTAGE
RANGE RESOLUTION ACCURACY
200V 100mV ± 1.2% of rdg ± 10D
600V 1V ± 1.2% of rdg ± 10D
OVERLOAD PROTECTION: 600V DC or 600Vrms for all ranges.
RESPONSE: Average, calibrated in RMS of a sine wave.
FREQUENCY RANGE: 45Hz-450Hz.
DC CURRENT
RANGE RESOLUTION ACCURACY
200 μ A100nA ± 1% of rdg ± 2D
2000 μ A 1 μ A ± 1% of rdg ± 2D
20mA 10 μ A ± 1% of rdg ± 2D
200mA 100 μ A ± 1.2% of rdg ± 2D
10A 10mA ± 2% of rdg ± 2D
OVERLOAD PROTECTION: 200mA 250V fuse
(10A range unfused).
MEASURING VOLTAGE DROP: 200mV.
RESISTANCE
RANGE RESOLUTION ACCURACY
200ohm 100m ohm ± 0.8% of rdg ± 2D
2000 ohm 1 ohm ± 0.8% of rdg ± 2D
20k ohm 10 ohm ± 0.8% of rdg ± 2D
200k ohm 100 ohm ± 0.8% of rdg ± 2D
2000k ohm 1k ohm ± 1% of rdg ± 2D
MAXIMUM OPEN CIRCUIT VOLTAGE: 2.8V.
OVERLOAD PROTECTION: 15 seconds maximum 220V rms on all
ranges.
AUDIBLE CONTINUITY
RANGE DESCRIPTION
·
··
·）））
））））））
））） Built-in buzzer sounds if resistance is less then 100 ohm
OVERLOAD PROTECTION: 15 seconds maximum 220V rms Sounds
alarm.

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TEMPERATURE (K TYPE PROBE)
RANGE RESOLUTION ACCURACY
-20 ℃ to 1370 ℃ 1 ℃ ± 3% ± 4D(up to 150 ℃ )
± 3% of rdg (over 150 ℃ )
OVERLOAD PROTECTION: 220Vrms AC.
OPERATING INSTRUCTIONS
WARNING
1. To avoid electrical shock hazard and/or damage of the instrument, do
not measure voltages that might exceed 500V above earth ground.
2. Before using the instrument, inspect test leads, connectors and probes
for cracks, breaks, or crazes in the insulation.
DC VOLTAGE MEASUREMENT
1. Connect red test lead to "V Ω mA" socket. Black lead to "COM"
socket.
2. Set RANGE switch to desired DCV position. If the voltage to be
measured is not known beforehand, set switch to the highest range and
reduce it until a satisfactory reading is obtained.
3. Connect test leads to device or circuit being measured.
4. Turn on power of the device or circuit being measured, voltage value
will appear on Digital Display along with the voltage polarity.
AC VOLTAGE MEASUREMENT
1. Red lead to "V Ω mA". Black lead to "COM".
2. RANGE switch to desired ACV position.
3. Connect test leads to device or circuit being tested.
4. Read voltage value on Digital Display.
DC CURRENT MEASUREMENT
1. Red lead to "V
Ω mA". Black lead to "COM". (For measurements
between 200mA and 10A connect red lead to "10A" socket, making sure
it is fully inserted).
2. RANGE switch to desired DCA position.

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3. Open the circuit to be measured, and connect test leads IN SERIES
with the load in which current is to be measured.
4. Read current value on Digital Display.
RESISTANCE MEASUREMENT
1. Red lead to "V Ω mA". Black lead to "COM".
2. RANGE switch to desired Ω Position.
3. If the resistance being measured is connected to a circuit, turn off
power and discharge all capacitors before measurement.
4. Connect test leads to circuit being measured.
5. Read resistance value on Digital Display.
DIODE MEASUREMENT
1. Red lead to "V Ω mA". Black lead to "COM".
2. RANGE switch to 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, figure "1" will be shown.
TRANSISTOR hFE MEASUREMENT
1. RANGE switch to the hFE position.
2. Determine whether the transistor is NPN or PNP type and locate the
Emitter, Base and Collector leads. Insert the leads into the proper holes
of the hFE Socket on the front panel.
3. The meter will display the approximate hFE value at the condition of
base current 10 μ Aand VCE 2.8V.
TEMPERATURE MEASUREMENT
1. Connect the K type thermocouple to "V Ω mA" and "COM".
2. RANGE switch to TEMP position.
3. The display will read the temperature value ℃ .
AUDIBLE CONTINUITY TEST
1. Red lead to "V Ω mA". Black lead to "COM".
2. RANGE switch to
·）））
·）））·）））
·））） position.
3 . Connect test leads to two points of circuit to be tested. If the resistance
is lower than 100 ohm, buzzer will sound.

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BATTERY AND FUSE REPLACEMENT
The fuse rarely needs replacement and blows almost always as a result
of operator error.
If "BAT" appears on display, it indicates that the battery should be
replaced.
To replace the battery and fuse (200mA/250V) remove the 2 screws in
the bottom of the case. Simply remove the old, and replace with a new
one. Be careful to observe battery polarity.
CAUTION
Before attempting to open the case of the instrument, be sure to
disconnect test leads from any energized circuits to avoid shock hazard.
ACCESSORIES
· Operator's instruction manual
· Set of test leads
· K type thermocouple
· 9 volt battery, PP3, NEDA 1604 6F22 TYPE (Optional).
READ AND UNDERSTAND THIS MANUAL
BEFORE USING THE INSTRUMENT.
Failure to understand and comply with the
WARNINGS and operating instructions
can result in serious or fatal injuries and/or
property damage.
WARNING

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Notice to customers
This symbol on the battery
indicates that the battery is to be
collected separately.
The following apply only to users
in European countries.
•This battery is designed
for separate collection at
an appropriate collection
point. Do not dispose of
as household waste
•For more information,
contact the retailer or
local authorities in charge
of waste management.
Maplin Electronics Ltd
Brookfields Way
Manvers
Wath-Upon-Dearne
Rotherham
S63 5DL
www.maplin.co.uk