Victor 81D User manual

DIGITAL MULTIMETER
OPERATION MANUAL
I. General
This is equipped with the LCD display
of text height 18.9mm, is a 3 3/4 digital
multimeter which has the merits of clear
reading, stable performance and high
reliability.
It could be used to measure DC voltage,
AC voltage, DC current, AC current,
resistance, temperature, capacity, frequency /
duty cycle, diode and make on-and-off test.
Meanwhile, it is available for unit symbol
display, automatic/manual range switching,
automatic power off and alarm function. The
complete machine takes an integrated circuit
which can directly drive LCD 8-bit
microprocessor and double-integrating A/D

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switching and a digital display drive offering
high resolution and high precision. Due to its
complete functions, high measurement
accuracy and convenient operation, the
multimeter is the ideal tool in laboratory and
factory as well as for radio fans and family.
Ⅱ. Open-package Inspection
Open the package box and take out the meter,
check carefully if the following accessories
are absent or damaged. If there is any absence
or damage, please contact the distributor
immediately.
Digital Multimeter 1 PC
Instruction Manual 1 copy
Test Leads 1 pair
Temperature Probe (K-Thermocouple) 1 PC
AAA (1.5v) 7# batteries 2 PCs

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Holster 1 PC
III. Safety Considerations
The design of meter is in accordance
with IEC1010 clause (the safety standard
issued by International Electrotechnical
Commission). Prior to the operation of the
instrument, please first read the safety
considerations.
1. When DC voltage above 30V, AC voltage
above 25V, current above 10mA, AC
power line with inductive load or power
line during electric fluctuation is measured,
please beware of electric shock.
2. Prior to measurement, check if the
measurement function switch is at the
correct position. Check if the meter pen is
contacted reliably, connected correctly, and

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grounded well and etc. in order to avoid
electric shock.
3. Only if the meter is used with the matched
meter pen, can it meet the requirement of
safety standard. When the line of the meter
pen is damaged, it is necessary to replace
another one of the same model or the same
electrical specification.
4. Don’t use other unconfirmed or
disapproved protector tube to replace the
protector tube inside the meter. Only the
protector tube of the same model or same
specification can be replaced. Before the
replacement, the test leads must leave the
measuring point and ensure there is no any
signal at the input terminal.
5. Don’t use other unconfirmed or
disapproved battery to replace the battery

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inside the meter. Only the battery of the
same model or same electrical
specification can be replaced. Before the
replacement, the test leads must leave the
measuring point and ensure there is no any
signal at the input terminal.
6. When the electrical measurement is made,
never let your body gets in touch with the
ground directly, and don’t touch uncovered
metal terminal, output port, lead clamp and
etc. where earth potential may exist. Dry
clothes, rubber shoes, rubber cushion and
other insulating material are usually used
to keep your body insulated against the
ground.
7. Don’t store and use it in the
high-temperature, high-humidity,
inflammable and strong magnetic field

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environment.
8. It may do damage to the meter and
endanger the operator’s safety if the
voltage value beyond the permitted
ultimate voltage value is measured. The
ultimate voltage value permitted for
measurement is marked on the instrument
panel, and never measure the value
exceeding the standard. Don’t input the
ultimate value out of regulation in order to
avoid electric shock and the damage to the
meter.
9. When the test leads is inserted into the
current socket, don’t measure any voltage
for fear that the meter should be damaged
and the operator’s safety be endangered.
10. Don’t try calibrating or repairing the
meter. When necessary, only the qualified

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professional personnel who have had
special training or gained approval can
make it.
11. During measurement, the requirement of
measurement function must be in
accordance with LCD display. Please be
sure to disconnect the line of the test leads
with the measured object first and ensure
there is no any input signal. It is forbidden
to switch the function/range selection
switch during measurement
12. When “ ” ”is shown on LCD
display, please replace battery
immediately to ensure the measurement
precision.
13. It is not allowed to insert the test leads
into the current terminal to measure
voltage!

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14. Please don’t change the circuits of the
meter freely for fear that the meter be
damaged and the safety be endangered.
15. Description of Safety Symbols
IV. Instrument Panel& Button Function
Description
1. Instrument Model Number
2.LCD Display: Display the
measured data and unit.
3. Function Button
3.1.SELECT(function
switch)：Press this
F
Hz
FUSED
400mA MAX
mA
V
COM
10A
C
Hz
1
2
3-1
3-2 3-3
3-4
4
5-1
5-2 5-3

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button, the function could switch
between DC/AC/
3.2. RANGE(auto/manual range switch):
it’s auto range switch after power-on,
press this key switch to manual range.
Under the manual range mode , Every
pressing to this key will make the range
get to upper one.press this key for more
than 2 sec. will back to auto range
mode .
3.3 . HOLD（Data Hold） ： Press this button,
the reading is locked; Press it again, the
lock is cleared and enter into normal
measurement status.
3.4 REL (Relative Value Measurement):
The relative value measurement of all
functions could be conducted by
pressing this button except the Hz/Duty

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function.(Frequency/duty cycle):press
this key to select frequency or duty
cycle measurement mode.
4.Knob Switch：It could be used to change
the measurement function and range.
5. Input Terminals
5.1.Current, Voltage, Diode, Resistance,
Capacity, Frequency, Buzzer,
Temperature“-”Input terminal.
5.2.10A“+”input terminal.
5.3.Voltage、Diode、Resistance, Capacity,
Frequency, Buzzer, Temperature and“+”
Input terminal with current less than
400mA.
V. Other Functions
Automatic Power off
During measurement, the meter will

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automatically shut down (enter sleeping
mode) to save power if function buttons and
knob switch are not operated in 15 minutes.
In auto power off mode, press any function
buttons or rotate the knob switch, the
instrument will get into the auto power on
mode (working mode); the auto power offer
mode will be cancelled by pressing the
SELECT button to turn turn on the
instrument.
VI、Property
1．General Property
1-1．Display：LCD
1-2．Max Display：3999（3 3/4）counts
automatic polarity display and unit
display
1-3．Measuring Method：Dual integral A/D

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converter
1-4．Sampling Rage：Approx. 3 times / sec.
1-5．Over Range Indication：Display“OL”
1-6．Low Battery Indication： “ ”symbol
appears；
1-7．Operation Environment: (0～40)℃，
Relative Humidity: ＜80% ；
1-8．Storage Environment: (0～50)℃，
Relative Humidity: ＜80% ；
1-9．Power: 2pcs 1.5V batteries (“AAA”7#
battery)
1-10．Dimension (size): 145×74×36mm
1-1 1 ．Weight: Approx. 190g（Including 2pcs
1.5V batteries）
1-12．Accessories: Instruction Manual (1 pc),
Holster (1 pc), Outer packing box (1 pc),
10A test leads (1 pair), K-Thermocouple
and 1.5V batteries (2 pcs).

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2．Technical Property
2-1. Accuracy:±(a%×reading＋digits)，at
(23±5)℃，relative humidity
＜75%. One year calibration
guarantee since the time
dispatched from the factory.
2-2.Technic Specification
2-2-1. DCV
1. Turn the knob switch to " " Range;
2. The initiate state of the meter is in
automatic range status, which shows
"AUTO" symbol;
3. Make the test leads contacted to the testing
point. The voltage and polarity of the
point where the red test lead is contacted
will be displayed on the screen.
Caution:
1. Don't measure voltage over 600V.

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Otherwise, there is a danger of meter
being damaged.
2. When measuring high voltage, special
attention should be given to personal
safety and avoid your body getting in
touch with high voltage circuit.
Range
Accuracy
Resolution
400mV
±(0.5%+4d)
100uV
4V
1mV
40V
10mV
400V
100mV
600V
±(1.0%+4d)
1V
Input Impedance: 400mV>40MΩ; 10MΩ at
other Ranges.
Overload Protection: 600V DC or 600V AC
Peak Value.

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2-2-2. ACV True RMS
1. Insert black test leads into the hole of
“COM” and red one into " ";
2. Rotate function switch to " " gear,
press “SELECT” button to select the AC
measurement mode.
3. The initiate state of the meter is in
automatic range status, which shows
“AUTO" symbol;
4. Make the test leads contacted to the testing
point. The voltage of the point where the
red pen is contacted will be displayed on
the screen.
Caution:
1. Don't measure voltage over 600V.
Otherwise, there is a danger of meter
being damaged.
2. When measuring high voltage, special

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attention should be given to personal
safety and avoid your body getting in
touch with high voltage circuit.
Range
Accuracy
Resolution
4V
±(0.8%+6d)
1mV
40V
10mV
400V
100mV
600V
±(1.0%+6d)
1V
Input Impedance: >10MΩ;
Overload Protection: 600V DC or 600V AC
Peak Value;
Frequency Response: (50～200) Hz;
Display: Average value response (RMS of
sine wave).
2-2-3. DCA
1. Insert the black test lead into the "COM"
input terminal and red one into the " "

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input terminal. (Max 400mA), or 10A
input terminal (Max 10A).
2. Rotate function switch to Current gear. The
initiate state of the meter is in automatic
range status, which shows "DC" symbol.
Then connect the test leads to the tested
circuit in serial, the tested current value
and the current polarity of the point where
the red one is contacted will be displayed
on the screen simultaneously.
Caution:
1. If “OL” is displayed on LCD, it indicates
the tested current value has exceeded the
present range limit, please select higher
range to complete the measurement.
2. The Max input value is 400mA or
10A.(Depending on the terminal where the
red test lead is contacted)

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Range
Accuracy
Resolution
400uA
±(1.0%+10d)
0.1uA
4000uA
1uA
40mA
10uA
400mA
100uA
10A
±(1.2%+10d)
10mA
Max measurement voltage drop: Full Range
mA is 0.4V, A is 100mV;
Max input current: 10A (less than 15
seconds);
Overload Protection: 0.4A/250V restorable
fuse, 10A/250V fuse.
2-2-4. ACATrue RMS
1. Insert the black meter pen into the
"COM" input terminal and red one into
the " " input terminal. (Max
400mA), or 10A input terminal (Max

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10A).
2. Rotate function switch to Current gear.
Press “SELECT” button to select the AC
measurement mode. Then connect the
test leads to the tested circuit in serial,
the tested current value and the current
polarity of the point where the red one is
contacted will be displayed on the screen
simultaneously.
Caution:
1. If “OL” is displayed on LCD, it indicates
the tested current value has exceeded the
present range limit, please select higher
range to complete the measurement.
2. The Max input value is 400mA or
10A.(Depending on the terminal where the
red test lead is contacted) The overrated
current will lead to fuse melt or even

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damage the meter.
Range
Accuracy
Resolution
400uA
±(1.5%+10d)
0.1uA
4000uA
1uA
40mA
10uA
400mA
100uA
10A
±(2.5%+15d)
10mA
Max measurement voltage drop: Full Range
mA is 0.4V, A is 100mV; Max input current:
10A (less than 15 seconds);
Overload Protection: 0.4A/250V restorable
fuse ，10A/250V fuse; Frequency
Response:True RMS response(50～200)Hz.
2-2-5. Resistance (Ω)
1. Insert the black meter pen into "COM"
terminal and red one into " " terminal.
2. Rotate the Range to “Ω” gear. Cross