Pro's Kit MT-1706 User manual

MT-1706
3-5/6 True-RMS Digital Multimeter
User’s Manual
1st Edition, 2018
©2018 Copyright by Prokit’s Industries Co., Ltd.

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1. General Information
This digital multimeter is designed and manufactured in compliance with
IEC-61010 safety requirements on electronic measuring instruments and
hand-held digital multi-meters. It is compliant with IEC-61010 requirements
pertaining to 600V CAT IV, 1000V CAT.Ⅲand requirements on pollution
degree 2. Please read carefully this operation manual and pay attention to
safety guidelines before operating this meter.
1.1 Safety information
1.1.1 Safety instructions
Before operating this meter, the operator must observe all standard safety
procedures in the two respects below:
A. Safety procedures against electric shock
B. Safety procedures against unintended use
To ensure your personal safety, please use the test lead that accompanies
the meter. Before operating this meter, ensure that the test lead is
flawless.
1.1.2 Safety considerations
When the meter is used in the vicinity of the equipment that produces
strong electromagnetic interferences, the reading on the meter will grow
unstable and even produce serious errors.
Don't operate the meter or pen-shaped meter whose appearance is
damaged.
The safety function of the meter will become null if the meter is not
properly operated.
The meter must be operated with great care when working in the vicinity
of an exposed conductor or bus line.
The meter is prohibited from being used in the vicinity of any explosive
gas, vapor or dust.
The measurement must be made with correct input terminals and
functions and within the allowable measuring range.
To prevent the meter from being damaged, the value to be input shall not
exceed the extremes allowed by each measuring range.
When the meter has already been connected to the line being measured,
the operator is prohibited from touching the input terminal that is not in
service.
When the voltage measured exceeds 60Vdc or 30Vac (valid value), the
operator shall be careful enough to avoid electric shock.
When making measurement with a test lead, place your fingers behind its

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protective ring.
When switching to another measuring range, be sure that test lead has
already been taken off the measured circuit.
For all DC functions, to prevent potential electric shock as a result of
incorrect reading, please first useAC functions to check the absence of
any AV voltage. Then, select DC voltage measuring range equivalent to or
greater than that for AC voltage.
Before the tests on electric resistance, diode, capacitor or continuity, the
operator must cut off the power supply to the circuit to be measured, and
discharge all high-voltage capacitors within the circuit to be measured.
The electric resistance measurement or continuity test cannot be carried
out in any live electrical circuit.
Before the current measurement, the operator must first examine the
protective tube of the meter. Before connecting the meter to the circuit to
be measured, the operator must first power off the aforesaid circuit.
Before repairing TV sets or measuring power switching circuit, the
operator must be careful enough to prevent high amplitude voltage
impulse from damaging the meter.
This meter uses 4 x 1.5V AA batteries that must be correctly installed into
the battery compartment.
When appears, the batteries must be replaced immediately. The low
level of a battery will result in incorrect reading on the meter, which is
likely to bring electric shock or personal injury to the operator.
In measurement, category III voltage and category IV voltage shall not
exceed 1000V and 600V respectively.
Themetershallnot be in service ifits case(or partof itscase)is dismantled.
1.1.3 Safety symbol:
The safety symbols that appear on the meter's body and in this Operation
Manual:
Warning, an important safety symbol. The operator
must consult this Operation Manual before using the
meter. Unintended use may lead to the damage to
the device or its components.
AC (alternating current)
DC (direct current)
AC/DC
Ground

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Double insulation protection
Fuse
High voltage warning
CAT.III1000V
over-voltage protection
CAT. IV 600 V
over-voltage protection
1.1.4 Maintenance practices for safety
The operator must first pull out the test lead when the meter's case is
opened or the battery cover is dismantled.
The designated replacement parts must be used at the moment of
maintenance.
The operator must cut off all relevant power supplies before opening the
meter. At the same time, the operator must avoid damage to the meter's
elements by ensure that he himself doesn't carry any static.
The meter can only be calibrated, repaired and maintained by
professionals.
When the meter's case is opened, the operator must understand the fact
that the presence of some capacitance may promise the dangerous
voltages even if the power supply to the meter is cut off.
The operator should stop using and maintain the meter immediately if any
abnormality has been observed on the meter. The operator must see to it
that the meter cannot be in service unless it is proved conforming.
When the meter is left idle for a long period, the operator shall remove the
battery and place it in a place free from high temperature and humidity.
1.2 Input protection measures
The meter can sustain the maximum input voltage of 1000V (DC) or 750V
(AC) at the moment of voltage measurement.
The meter can sustain the maximumAC voltage of 600V or equivalent
voltage (valid value) when the tests on frequency, electric resistance,
continuity and diode are carried out.
The protective tube (FF630mA/250V) is used for protection purpose when
A and mAcurrent measurements are carried out.

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2. A Schematic Diagram for
the Meter
This meter is a hand-held digital
multi-meter with the function of
displaying True RMS. it is a
large-screen LCD unit with backlight
and illumination light functions so
that the user can easily recognize
reading. It is equipped with the
function of overload protection and
the indicator of battery under voltage.
Either for professionals, factories,
schools, enthusiasts or households,
it is an ideal multi-functional meter.
2.1 A Schematic Diagram for
the Meter
Physical appearance
①.Non-contact voltage detection area
②.Non-contact voltage indicator
③.LCD screen
④.hFE socket
⑤.Key
⑥.Rotary switch
⑦.Input socket
2.2 Description of the symbols on the display unit
Fig. 1 (Display panel)

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Table.1 Symbols
Symbol
Description
Battery under voltage indicator/ Low Battery
To avoid electric shock or personal injury as a
result of incorrect reading, promptly replace the
battery when the battery under voltage indicator
appears.
Auto power off indicator
High voltage warning
Negative input polarity indicator
Input voltage AC
Input voltage DC
Continuity test mode
Diode test mode
Automatic range measurement mode
Data hold mode
℃，℉
Unit of temperature(℃: Celsius; ℉: Fahrenheit)
%
Duty ratio
NCV
Non-contact AC voltage detection mode
Live
Live line judgment mode
hFE
HFE test mode
Table.1 Symbols (Continued)
V, mV
V:
mV：
V: the unit of volt
Millivolt，1x10-3 or 0.001 volt.
A, mA, A
A:
mA:
A:
Ampere, the unit of current.
Milliampere, 1x10-3 or 0.001 ampere.
Microampere, 1x10-6 or 0.000001
ampere.
, k, M
:
k:
M:
Ohm, the unit of electric resistance.
Kilohm, 1000 Ohm
Megaohm, 1,000,000 ohm.
MkHz
Hz:
KHz:
MHz:
Hz, the unit of frequency
KHz, 1x103Hz.
MHz, 1x106Hz or 1000 KHz.

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mF,F, nF
F:
mF:
F:
nF:
Farad, the unit of capacitance.
Millifarad, 1x10-3 or 0.001 farad.
Microfarad, 1x10-6 or 0.000001 farad.
nF, 1x10-9 or 0.000000001 farad.
2.3 Description of functional keys
Key
Description of functions
SEL
SEL keys, e.g.
Temperature measurement position: ℃mode or ℉
mode.
Frequency measurement position: HZ measurement
mode or duty ratio (%) measurement mode
AC voltage position and AC current position: press
the key to select voltage/frequency mode or
current/frequency mode in the AC voltage
measurement mode orAC current measurement
mode.
HOLD
Press the key to hold the measured value for the
current moment Press the key again to cancel this
function.
Press the key for 2 seconds and more, the
backlight and the illumination indicator will be
on; however, with another 2-second press on
the same key, you will turn off backlight and
illumination indicator. If you don't press the key
at all, the function will automatically be
disenabled in 15 minutes.
2.4 Description of input socket
Input socket
Description
COM
All public input terminals to be measured are
connected to test leads in black or the public output
plugs of exclusive multi-function test sockets.
℃/℉
VHz%
lives
Positive input terminals (connected to a test lead in
red) for capacitor measurement, diode
measurement, beep on/off test, temperature
measurement, voltage measurement, electric
resistance, frequency, duty ratio and live/earth line
judgment.
A mA
A and mA positive input terminal (connected to a
test lead in red).
20A
20A positive input terminal (connected to a test lead
in red).

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2.5 Accessories
1.Operation Manual
X 1
2. Test lead
X 1 pair
3.K-Type thermocouple
X 1
3. Operational guidelines
3.1 Normal operation
3.1.1 Hold mode
In the hold mode, the reading can be maintained on the display unit.
Changing the measurement function position or pressing the key.
Hold again to exit the hold mode
Hold mode: entry and exit
1. Press the key “H/ ” and the reading will be held and the symbol
“ ” will appear on the LCD screen.
2. Press the key “H/ ” again to restore the meter to its status for
normal measurement.
3.1.2 Backlight
The meter is equipped with the functions of backlight so that the operator
can access measurement results even if he is in a darker place. The
backlight function can be enabled or disenabled by the steps below:
1. Press the key" H/ " for over 2 seconds to enable backlight .
2. Press the key" H/ " for over 2 seconds to again to manually
disenable backlight; wait for 15 seconds until the backlight is
automatically disenabled.
3.1.3 Auto power off
If no operations are made in 15 minutes following the initialization, the meter
will sound to remind the operator to automatically cut off power supply and
enter the state of dormancy. The meter can be rebooted when the operator
presses any key in the auto power off mode.
3.2 Measurement guidelines
3.2.1 Measurement of AC voltage and DC voltage

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To avoid any electric shock and/or damage to the meter, do
not attempt a voltage measurement if the voltage (valid
value) is 1,000V for DC current or 750V for AC current.
To avoid any electric shock and/or damage to the meter,
don't attempt to impose between any public terminal and
ground any voltage whose valid value is over 1,000V for DC
current or 750V for AC current.
The meter provides DC voltage measuring ranges as follows: 600.0mV,
6.000V, 60.00V, 600.0V and 1000V, and AC voltage measuring ranges:
6.000V, 60.00V, 600.0V and 750V.
Measurement of AC voltage or DC voltage
Turn the rotary switch to the position ～V or V.
Connect the test lead in black and test lead in red to COM input socket
and V input socket respectively.
Use another two ends of the test lead to measure the voltage of the
circuit to be measured. (In parallel connection with the circuit to be
measured)
Read the measured voltage value on LCD screen. When DC voltage
measurement is attempted, the display unit will show the voltage
polarity of the circuit connected to the pen-shaped meter in red.
Notes:
Within the measuring range of DC voltage of 600mV and AC voltage of
6V, even if there is no input or no connection to the test lead, the meter
will display some information. In this situation, press short circuit “V－
” and “COM” terminal to reset the meter to zero.
Within theAC voltage function, press the key "SEL" to measure the
frequency of theAC voltage source. Please refer to the relevant part for
frequency measurement.
The value of theAC voltage measured with this meter is True RMS (root
mean square). These measurements are accurate for sine wave and
other waves (without DC offset), square wave, triangular wave and step
wave.
3.2.2 Electric resistance measurement
To avoid the meter or the measured equipment from damage,
do not attempt a resistance measurement unless the operator
has already cut off all power sources for the circuit to be

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measured and fully discharged all high-voltage capacitors.
Ohm is the unit of electric resistance ().
The measuring ranges of electric resistance of this meter are 600.0,
6.000k, 60.00k, 600.0k, 6.000Mand 60.00M,
Measurement of electric resistance
1. Turn the rotary switch to the appropriate position.
2. Connect the test lead in black and test lead in red to COM input
socket and V/input socket respectively.
3. Use another two ends of the test lead to measure the electric
resistance of the circuit to be measured.
4. Read the measured electric resistance value on LCD screen.
Notes:
The measured value of the electric resistance of the circuit differs a
bit from the rated value of the electric resistance.
To ensure measurement accuracy, in attempting a low resistance
measurement, first put two pen-shaped meters in short circuit and
capture the resistance reading of these short circuits. Then subtract
the aforesaid reading from the measured resistance.
At 60Mposition, you have to wait a few seconds before the reading
grow stable. This is quite normal for a high resistance
measurement.
When the meter is in open circuit, the display unit will show "OL" that
indicates the measured value is over the measuring range.
3.2.3 Diode test
To avoid the meter or the measured equipment from damage,
do not attempt a diode test unless the operator has already
cut off all power sources for the circuit to be measured and
fully discharged all high-voltage capacitors.
Diode test outside the circuit:
1. Turn the rotary switch to the position .
2. Connect the test leads in black and in red to COM input socket and
V/input socket respectively.
3. Connect the test leads in black and in red to the positive and
negative poles of the diode to be tested respectively.
4. The meter displays the forward bias value of the diode to be tested. If