OPERATING INSTRUCTIONS
ELENCO M-1740
DIGITAL MULTIMETER
OPERATION
Before taking any measurements, read the Safety Information
Section. Always examine the instrument for damage,
contamination (excessive dirt, grease, etc.) and defects.
Examine the test leads for cracked or frayed insulation. If any
abnormal conditions exist, do not attempt to make any
measurements.
Voltage Measurements
1. Connect the red test lead to the “V
Ω
A” jack and the black
test lead to the “COM” jack.
2. Set the Function/Range switch to the desired current range
and slide the “AC/DC” selector switch to the desired
voltage type. If magnitude of voltage is not known, set
switch to the highest range and reduce until a satisfactory
reading is obtained.
3. Connect the test leads to the device or circuit being
measured.
4. For DC, a (-) sign is displayed for negative polarity;
positive polarity is implied.
Current Measurements
1. Set the Function/Range switch to the desired current range
and slide the “AC/DC” selector switch to the desired
current type.
2. For current measurements less than 200mA, connect the
red test lead to the “V
Ω
A” jack and the black test lead to
the COM jack.
3. For current measurements over 200mA or greater, connect
the red test lead to the 10A jack and the black test lead to
the COM jack.
SAFETY INFORMATION
The following safety information must be observed to insure
maximum personal safety during the operation of this meter:
1. Do not use the meter if the meter or test leads look
damaged, or if you suspect that the meter is not operating
properly.
2. This meter is not recommended for high voltage industrial
use; for example, not for measurements of 440VAC or
600VAC industrial power mains. The unit is intended for
use with low energy circuits to 600V AC/DC or high
energy circuits to 250VAC or DC. Accidental misuse by
connection across a high voltage, high energy power
source when the meter is set up for mA measurement may
be very hazardous.
3. Turn off power to the circuit under test before cutting,
unsoldering, or breaking the circuit. Small amounts of
current can be dangerous.
4. Use caution when working above 60VDC or 30VAC rms.
Such voltages pose a shock hazard.
5. When using the probes, keep your fingers behind the
finger guards on the probes.
6. Measuring voltage which exceeds the limits of the
multimeter may damage the meter and expose the operator
to a shock hazard. Always recognize the meter voltage
limits as stated on the front of the meter.
7. If the equipment is used in a manner not specified by the
manufacturer, the protection provided by the equipment
may be impaired.
4. Remove power from the circuit under test and open the
normal circuit path where the measurement is to be taken.
Connect the meter in series with the circuit.
5. Do not continually measure 10A as the shunt wire will
heat up. Allow 60 seconds max. At 5A or less, continuous
use is OK.
Resistance and Continuity Measurements
1. Set the Function/Range switch to the desired resistance
range or continuity position.
2. Remove power from the equipment under test.
3. Connect the red test lead to the “V
Ω
A” jack and the black
test lead to the “COM” jack.
4. Touch the probes to the test points. In ohms, the value
indicated in the display is the measured value of resistance.
In continuity test, the beeper sounds continuously, if the
resistance is less than 40
Ω
+/-20
Ω
.
WARNING
The accuracy of the functions might be slightly affected
when exposed to a radiated electromagnetic field
environment, e.g. radio, telephone or similar.
Diode Tests
1. Connect the red test lead to the “V
Ω
A” jack and the black
test lead to the “COM” jack.
2. Set the Function/Range switch to the “ ” position.
3. Turn off power to the circuit under test.
4. Touch probes to the diode. A forward-voltage drop is
about 0.6V (typical for a silicon diode).
5. Reverse probes. If the diode is good, “OL” is displayed.
If the diode is shorted, “.000” or another number is
displayed.
SPECIFICATIONS
Display:
3 1/2 digit liquid crystal display (LCD) with a
maximum reading of 1999.
Polarity:
Automatic, positive implied, negative polarity
indication.
Overrange: (OL) or (-OL) is displayed.
Zero: Automatic.
Low Battery Indication: The “ ” is displayed when the
battery voltage drops below the operating level.
Measurement Rate: 2.5 times per second, nominal.
Operating Environment:
0
O
C to 40
O
C at <70% relative
humidity.
Storage Temperature: -20
O
C to 60
O
C, 0 to 80% R.H. with
battery removed from meter.
Accuracy: Stated accuracy at 23
O
C +/-5
O
C, <75% relative
humidity.
Safety: According to EN61010-1 protection class II over-
voltage category (CAT II 600V) pollution degree 2.
Power:
Single standard 9-volt battery, NEDA 1604, JIS
006P, IEC 6F22.
Battery Life: 150 hours typical with carbon-zinc.
Dimensions: 151mm (H) x 70mm (W) x 38mm (D).
Weight: Approx. 7 oz. (200g.) including battery.
Accessories: One pair test leads, one spare fuse, 9V battery
(installed) and operating instructions.
6. If the diode is open, “OL” is displayed in both directions.
7. If the junction is measured in a circuit and a low reading is
obtained with both lead connections, the junction may be
shunted by a resistance of less than 1k
Ω
. In this case, the
diode must be disconnected from the circuit for accurate
testing.
Transistor Gain Measurements
1. Set the Function/Range switch to the desired h
FE
range
(PNP or NPN type transistor).
2. Never apply an external voltage to the h
FE
socket. Damage
to the meter may result.
3. Plug the transistor directly into the h
FE
socket. The sockets
are labeled E, B, and C for emitter, base and collector.
4. Read the transistor h
FE
(DC gain) directly from the display.
Frequency Measurements
1. Set the Function/Range switch to the Hz position.
2. Connect the red test lead to the “V
Ω
A” jack and the black
test lead to the “COM” jack.
3. Connect the test leads to the point of measurement and
read the frequency from the display.
Capacitance Measurements
1. Set the Function/Range switch to the desired F
(capacitance) range.
2. Never apply an external voltage to the Cx sockets.
Damage to the meter may result.
3. Insert the capacitor leads directly into the Cx socket.
4. Read the capacitance directly from the display.
+
MAINTENANCE
Battery Replacement
Power is supplied by a 9 volt “transistor” battery (NEDA
1604, IEC 6F22). The “ ” appears on the LCD display
when replacement is needed. To replace the battery, remove
the two screws from the back of the meter and lift off the front
case. Remove the battery from battery contacts.
Fuse Replacement
If no current measurements are possible, check for a blown
overload protection fuse. There are two fuses; F1 for the
“V
Ω
A” jack and F2 for the 10A jack. For access to fuses,
remove the two screws from the back of the meter and lift off
the front case. Replace F1 only with the original type
0.8A/250V, fast acting fuse. Replace F2 only with the
original type 10A/600V, fast acting ceramic fuse.
Cleaning
Periodically wipe the case with a damp cloth and detergent,
do not use abrasives or solvents.
753054
WARNING
Remove test leads before changing battery or
performing any servicing.
+
DC Accurac
y
A
C Accurac
y
Input Impedance
Maxim
um Input
V
olta
g
e
+/-(1.9%rdg+4dgts)
500VDC or A
C
rm
s
(A
C 50Hz - 500Hz)
+/-(0.5%rdg+1dgt)
on 600V r
ange
10M
Ω
on 200mV r
ange
+/-(1.0%rdg+4dgts)
600VDC or A
C
rm
s
on all other r
anges
on all other r
anges
Current A
DC Accur
acy
A
C
Accur
acy
V
oltage Burden
Input Protection
mA
+/-(1.0%rdg+1dgt)
+/-(2.0%rdg+4dgts)
0.7V
0.5A/250V fuse
10A
+/-(3.0%rdg+1dgt)
+/-(3.5%rdg+4dgts)
1.2V
10A/600V fuse
Rang
e
Accurac
y
T
est Condition
Input Pr
otection
200
Ω
+/-(0.8%rdg+3dgts)
3.0VDC
Ohm
2k
Ω
- 2,000k
Ω
+/-(0.8%rdg+1dgt)
0.3VDC
20M
Ω
+/-(3.0%rdg+3dgts)
0.3VDC
500VDC or A
C
rm
s
Diode
2V
+/-(3.0%rdg+3dgts)
1mA +/-0.6mA
Contin
uity
200
Ω
<40
Ω
+/-20
Ω
Beeper <40
Ω
3.0VDC
Capacitance
2,000pF - 20
µ
F
+/-(2.0%rdg+10dgts)
2.5Hz 3V
h
FE
0-1,000
N/A
lb = 10
µ
A appro
x
.
Vce<3.5V
Frequenc
y
2kHz - 15MHz
+/-(0.1%rdg+1dgt)
Sensitivity
500VDC or A
C
rm
s
(auto-r
ange)
(10Hz - 15MHz)
1.5Vr
m
s
