Pro's Kit mt-1232 User manual

MT-1232
3-3/4 Autorange Digital Multimeter
User’s Manual
2st Edition,2012
©2012 Copyright by Prokit’s Industries Co., Ltd.

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Contents
General------------------------------------------------------------------1
Open-Package Inspection------------------------------------------2
Safety Note -------------------------------------------------------------2
Instrument Panel& Button Function Description---------------5
Other Functions--------------------------------------------------------6
Properties----------------------------------------------------------------6
Instrument Maintenance--------------------------------------------16
Fault Elimination------------------------------------------------------17
General
This product equipped with the LCD display of text height 15mm,
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, 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 multimeter, due to its complete functions,
performs with high measurement accuracy and convenient
operation, and is ideal for general electrical testing and
troubleshooting

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Open-package Inspection
Open the package box and take out the meter, check carefully
if the following accessories are missing or damaged. If there
is anything missing or damaged, please contact the distributor
immediately.
Digitalmultimeter 1PC
User’smanual 1copy
Test leads 1 pair
Temperature Probe (K-Thermocouple) 1 PC
Safety Note
The design of this meter is in accordance with IEC1010 clause
(the safety standard issued by International Electrotechnical
Commission). Prior to the operation of the instrument, please
read the safety considerations before use.
1. When DC voltage is 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 test lead is
contacted reliably, connected correctly, and grounded well
etc. in order to avoid electric shock.
3. Only if the meter is used with the matched test lead, does it
meet the requirement of the safety standard. When the line
of the test lead is damaged, it is necessary to replace with
another one of the same model or the same electrical
specification.
4. Don’t use other unconfirmed or disapproved fuses to replace
the fuse inside the meter. Only the same model or same
specification fuse can be replaced. Before the replacement,

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the test leads must be removed from 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 inside the meter. Only the same model or
same electrical specification battery can be replaced. Before
the replacement, the test lead must be removed from 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 environment.
8. It may 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 lead 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 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 lead 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 lead into the current
terminal to measure voltage!
14. Please don’t change the circuits of the meter freely for fear
that the meter will be damaged and the safety endangered.
15. Description of Safety Symbols
Warning! DCV
High
Voltage!
Danger! ACV
DCA
Ground
ACA
Double
Insulation
In accordance with the
instruction of European
Trade Union
Low
Battery Fuse
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Instrument Panel & Function Button Description
1. Instrument model number
2. LCD Display: Displays the measured data and unit.
3. Function Button
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3.1 Hz/% (Frequency/Duty Cycle)
Press this button to select the
frequency or duty cycle mode.
The measurement mode of
voltage/frequency/duty cycle or
current/frequency/duty cycle
could be selected by pressing
this button in AC/DC voltage or
AC/DC current .
3.2 REL (Relative Value
Measurement): The relative value measurement of
Capacitance function could be conducted by pressing this
button
3.3 D/¤ :( Data hold/ Backlight): Press the left side of this
button, the reading is locked; press it again (the left side),
the lock will release and back to normal measurement
status. Press the right side of this button over 3 seconds,
the backlight will come on, press this button(the right side)
again the backlight turns off.
3.4 S: (Function Switch): Press this button, the function could
switch between DC/AC and
4. Knob Switch: Used to change the measurement function and
range.
5. Input Terminals
5.1. Current, Voltage, Diode, Resistance, Capacitance,
Frequency, Buzzer, Temperature “-” Input terminal.
5.2.10A“+”input terminal.

5.3. Voltage, Diode, Resistance, Capacitance, Frequency,
Buzzer, Temperature and“+” Input terminal with current
less than 400mA.
Other Functions
Auto Power off
During measurement, the meter will automatically shut down
(enter sleeping mode) to save power if function buttons and
knob switch are not operated for 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)
Properties
General Feature
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 converter
1-4 Sampling Range: Approx. 3 times / sec.
1-5 Over Range Indication: Display “OL”
1-6 Low Battery Indication: “ ” symbol appears;
1-7 Operation Environment: (0~40)˚C Relative Humidity:<80%
1-8 Storage Environment: (0~50)˚C Relative Humidity:<80%
1-9 Power: 2 pcs 1.5V batteries (“AA” battery)
1-10 Dimension (size): 147×78×41mm
1-11 Weight: Approx. 183g
1-12 Accessories: User’s Manual (1 pc), color box (1 pc), 10A
test leads (1 pair), K-Thermocouple .
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Technical Features
2-1. Accuracy: ± (a%× reading +digits),at (23±5)˚C, relative
humidity<75%. One year calibration guarantee from the
time dispatched from the factory.
2-2. Technical Specification
2-2-1. DCV
A) Turn the knob switch to “ “Range
B) The default state of the meter is automatic range status,
which shows “AUTO” symbol
C) Put the test lead in contact with the testing point. The voltage
and polarity 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 the 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 100uV
4V 1mV
40V 10mV
400V
±(0.5%+4d)
100mV
600V ±(1.0%+4d) 1V
Input Impedance: 400m >40MΩ; 10MΩat other Ranges.
Overload Protection: 600V DC or 600V AC Peak Value.
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2-2-2. ACV
A) Insert black test lead into the hole of “COM” and red test
lead into “ “
B) Rotate function switch to “ “, press “SELECT” button to
select the AC measurement mode.
C) The default state of the meter is in automatic range status,
which shows “AUTO” symbol
D) Put the test lead in contact with the testing point. The voltage
of the point where the red test lead is contacted will be
displayed on the screen.
Caution:
1. Don’t measure voltage over 600V. ; Otherwise, the meter will
be 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
4V 1mV
40V 10mV
400V
±(0.8%+6d)
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).
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2-2-3. DCA
A) Insert the black test lead into the “COM” input terminal and
red test lead into the “ “input terminal. (Max 400mA),
or 10A input terminal (Max 10A).
B) Rotate function switch to Current. The default state of the
meter is in automatic range status, which shows “DC”
symbol. Then connect the test lead to the tested circuit in
series, the tested current value and the current polarity of
the point where the red pen 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)
Range Accuracy Resolution
400uA 0.1uA
4000uA 1uA
40mA 10uA
400mA
±(1.0%+10d)
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.
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2-2-4. ACA
A) Insert the black test lead into the “COM” input terminal and
red test lead into the “ “input terminal. (Max 400mA),
or 10A input terminal (Max 10A).
B) Rotate function switch to Current. Press “SELECT” button to
select the AC measurement mode. Then connect the test
lead to the tested circuit in series, the tested current value
and the current polarity of the point where the red test lead
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 damage the meter.
Range Accuracy Resolution
400uA 0.1uA
4000uA 1uA
40mA 10uA
400mA
±(1.5%+10d)
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: 10A Range (50~200)Hz.
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2-2-5. Resistance (Ω)
A) Insert the black test lead into “COM” terminal and red test
lead into “ “terminal.
B) Rotate the Range to “Ω”. Cross connect the two test leads
to the tested resistor.
C) When measuring the low resistance, please short-circuit the
test leads at first to test the wire resistance, and then deduct
it from the actual resistance.
Caution:
1. If “OL” is displayed on LCD, it indicates the tested resistance
value has exceeded the present range limit, please select
higher range to complete the measurement. When measuring
the Resistor higher than 1MΩ, the instrument will take several
seconds to make the reading stable. It is normal when
measuring the high resistor.
2. When the input terminal is open circuit, it will display “OL”.
3. When measuring in-line resistor, be sure that the power is off
and all capacitors are discharged completely.
Range Accuracy Resolution
400Ω±(0.8%+5d) 0.1Ω
4kΩ1Ω
40kΩ10Ω
400kΩ100Ω
4MΩ
±(0.8%+4d)
1kΩ
40MΩ±(1.2%+10d) 10kΩ
• Open Voltage circuit: Less than 200mV;
• Overload Protection: 250V DC or AC Peak Value;
Note: When measuring at Range 400Ω, please short-circuit the
test leads at first to test the wire resistance, and then deduct
it from the actual resistance.
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2-2-6.Diode and Continuity Test
A) Insert the black test lead to “COM” terminal and the red test
lead to “ ” terminal. (The polarity of red test lead is“+”).
B) Rotate the Range to “ “. Press “SELECT” button to
select the Diode measurement mode.
C) Forward Measurement: Connect the red test lead to the
diode positive polarity and the black test lead to the diode
negative polarity. The approximate value of diode forward
voltage drop will show on the display.
4. Backward Measurement: Connect the red test lead to the
diode negative polarity and the black test lead to the diode
positive polarity. “OL” symbol will be displayed on the
screen.
5. The complete diode testing includes forward and backward
measurement, if the result does not meet the above; it
means the diode is bad.
6. Press “S” button to select the Continuity measurement
mode.
7. Connect the test leads to two points of the tested circuit. If
the built-in buzzer sounds, the resistance between the two
points is less than 50Ω.
Range Display Test Condition
Forward Voltage
Drop of Diode
Forward DC Current is
Approx. 0.5mA, Backward
Voltage is Approx. 1.5V
Buzzer makes
a long sound if
resistance is less
than 50Ω
Open circuit voltage is
Approx. 0.5V
• Overload Protection: 250V DC or AC Peak Value.
CAUTION: DO NOT INPUT VOLTAGE AT THIS RANGE!
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2-2-7. Capacitance (F)
A) Rotate function switch to “ “.
B) Insert the black test lead to “COM” terminal and red test
lead to “ “ terminal;
C) Connect the tested capacity by the test leads to “COM”,
““ input terminal, the screen will show capacitance
parameter. (The relative value measurement could be
conducted by pressing “REL” button.)
Caution:
1. Fully discharge the tested capacitor in case it damages the
meter.
2. When measuring in-line capacitor, the power should be turned
off and all capacitors should be discharged completely.
3. It takes about 30 seconds to input stable reading at 100uF
Range.
Range Accuracy Resolution
4nF ±(5.0%+9d) 1 pF
40nF 10pF
400nF 100pF
4μF 1nF
40μF
±(3.5%+8d)
10nF
100μF ±(5.0%+8d) 100nF
• Overload Protection: 250V DC or AC Peak Value.
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2-2-8. Frequency (Hz)
A) Connect test leads and shielded cable to “COM”, “ ”
terminals.
B) Rotate function switch to “Hz”. Connect test leads and the
cable to the signal source or the tested load. The tested
signal will show on the screen.
Caution:
1. When inputting AC RMS over 10V, it could show reading, but
excess vibration may appear.
2. It is recommended to test weak signals by shielded cable
under noisy circumstances.
3. Select ACV when testing the frequency of high voltage. Then
press “Hz/DUTY” button to enter frequency measurement
status.
4. Don’t input voltage of over 250V DC or AC peak value in case
it damages the meter.
Range Accuracy Resolution
1Hz 0.001Hz
10Hz 0.01Hz
100Hz 0.1Hz
1kHz 1Hz
10kHz 10Hz
100kHz 100Hz
1MHz 1kHz
10MHz
±(0.5%+10d)
10kHz
0.1-99.9% For your reference 0.1V
• Input Sensitivity: >0.7V RMS
• Overload Protection: 250V DC or AC Peak Value.
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2-2-9. Temperature (˚C)
A) Rotate function switch to (˚C).
B) Insert the cathode (black pin) of cold end (free end) of
thermocouple into “COM” jack and anode into “ ”
terminal. Then put the working end (temperature
measurement end) of thermocouple on the surface or inside
the object to be tested. Then you can read temperature from
the screen, and the data is in Centigrade.
Caution:
1. When the input terminal is open-circuit, it will display the
normal temperature.
2. Don’t change the temperature probe at random, or the value
accuracy could not be guaranteed.
3. Don’t measure voltage at temperature range.
Range Accuracy Resolution
(-20~1000)˚C <400˚C±(1.0%+5d)
≥400˚C±(1.5%+15d)
1˚C
• Sensor: K Type Thermocouple (Nickel-chromium--nickel
silicon) (banana plug).
Caution: DO NOT INPUT VOLTAGE AT THIS RANGE!
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Instrument Maintenance
This is a precision instrument and the user shall not modify the
electric circuit as well.
1. Keep the instrument away from water, dust and shock.
2. Do not store and operate the meter under the condition of high
temperature, high humidity, combustible, explosive and strong
magnetic place.
3. Wipe the case with a damp cloth and detergent; do not use
abrasives and alcohol.
4. If the instrument is not operated for a long time, please take
out the battery to avoid leakage.
5. Pay attention to the status of the 1.5v battery. When the LCD
displays a flashing “ ”symbol, the battery shall be replaced.
The steps are as follows:
5-1. Loosen the screw on the back cover that secures the
battery case and remove the battery case.
5-2. Remove the 1.5V batteries and replace them with two
new ones. Although a 1.5V battery of any standard can be
used, but in order to lengthen the operation life, alkaline
batteries should be used.
5-3. Mount the battery case back and tighten the screw.
Precaution:
1. Don’t input voltage higher than DC 1000V or AC Peak Value.
2. Don’t measure voltage at current, resistance, diode and
buzzer range.
3. Don’t use the instrument when the battery has not been
mounted properly or the back cover ahs not been tightened.
4. Prior to the replacement of battery or fuse, please remove the
test leads from the measuring point and switch off the meter.
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Fault Elimination
If the instrument does not work properly, please try the following
tips to solve some general problems. If the problems still exist,
please contact the maintenance center or the distributor.
Fault Solution
No Display Turn on power.
Replace battery
symbol appearance Replace battery.
Big display error Replace battery
This Instruction is subject to change without any further notice.
The content of this Instruction is considered correct, and in
case readers find any errors and missing parts, please contact
the manufacturer.
The Company shall not be held liable for any accidents and
hazards resulted from the mal-operations by the user.
The function elaborated by this Instruction shall not be taken
as the reasons for using the product for special purposes.
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目 錄
一.概述-------------------------------------------------------------------------18
二.開箱檢查-------------------------------------------------------------------18
三.安全注意事項-------------------------------------------------------------19
四.儀錶面板及按鍵功能說明---------------------------------------------20
五.其他功能------------------------------------------------------------------- 21
六.特性------------------------------------------------------------------------- 21
七.儀錶保養------------------------------------------------------------------- 29
八.故障排除------------------------------------------------------------------- 30
一、概述
MT-1232 是一款性能穩定、高可靠性 3 3/4 位元數字多用錶。儀
錶採用 15mm 字高 LCD 顯示器，讀數清晰。
可用來測量直流電壓、交流電壓、直流電流、交流電流、電阻、
溫度、電容、頻率/占空比、二極體及通斷測試。同時還設計有
單位符號顯示、自動/手動量程轉換、自動斷電及報警功能。該錶
功能齊全，測量準確度高，使用方便，是實驗室、工廠、無線電
愛好者及家庭的理想工具。
二、開箱檢查
打開包裝箱取出儀錶，仔細檢查以下附件是否缺少或損壞，
如有缺少或損壞請立即與經銷商聯繫。
● 數字多用錶 一台
● 使用說明書 一本
● 錶棒 一付
● 溫度探頭(K 型熱電偶) 一隻
● 防震套（裝於電錶上） 一個

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三、安全注意事項
該儀錶在設計上符合 IEC1010 條款（國際電工委員會頒佈的安全標
準），在使用之前，請先閱讀安全注意事項。
1. 在測量直流 36V、交流 25V 以上電壓,測量 10mA 以上電流,測
量帶電感負載的交流電力線;測量電力波動期間的交流電力線
時, 謹防電擊。
2. 測量前，檢查測量功能開關是否置於正確的檔位,要檢查錶筆
是否可靠接觸，是否正確連接、是否絕緣良好等，以避免電
擊。
3. 儀錶只有和所配備的錶棒一起使用才符合安全標準要求。如
錶棒線破損時,必須更換上同樣型號或者相同電氣規格的錶棒
線
4. 不要使用其他未經確認或未認可的保險管來更換儀錶內部的
保險管。只能換上同樣型號或相同規格的保險管。更換前,錶
棒必須離開被測量點,確保輸入端無任何信號。
5. 不要使用其他未經確認的電池來更換儀錶內的電池。只能換
上同型號或相同電氣規格的電池。更換前,錶棒必須離開被測
量點,確保輸入端無任何信號。
6. 在進行電氣測量時,身體切勿直接接觸大地,不要接觸可能存
在地電勢裸露的金屬端子、輸出口、引線夾等。通常使用乾
燥的衣服、膠鞋、膠墊以及其他絕緣材料,保持你的身體與大
地絕緣。
7. 不要在高溫、高濕、易燃、易爆和強磁場環境中存放及使用。
8. 測量超過儀錶所允許的極限電壓值有可能損壞儀錶和危及操
作人員的安全。在儀錶面板上標有儀錶所允許測量的極限電
壓值切勿測量超過此標準的安全,請勿輸入超過規定的極限
值，以防電擊和損壞儀錶。
9. 當錶棒線插入電流插座時切勿測量任何電壓以免損壞儀錶和
危及操作人員的安全。
10. 不要嘗試校準或維修儀錶。的確有需要時必須有專門培訓或
認可的有資格專業人員才能進行。