Pro's Kit MT-1820 User manual

VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECTRANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
V
Professional Digital
Multimeter
MT-1820
User’s Manual

1
Index
General 2
Open Package Inspection 2
Safety Note 2
Safety Symbol Description 4
Front Panel Description 5
Property 6
DC Voltage (DCV) 6
AC Voltage (ACV) 7
DC Current (DCA) 8
AC Current (ACA) 9
Resistance 11
Diode and Continuity Test 12
Capacitance (C) 12
Frequency (Hz) 13
Transistor Test 14
Temperature Test 15
Other Function & Instrument Maintenance 16

2
General
The instrument is a high performance, high accuracy, 3 5/6 digit multi-meter,
it uses the LCD with 33mm high gure to make the reading clear, the display
simple and the operation convenient.
The instrument can measure DC and AC voltage, DC and AC current, Resis-
tance, Capacitance, Frequency, Duty Circle, Transistor, Diode and Continuity
test; And it also has the features of Bar Graph, Unit Indication, Data Hold,
Relative Value Measurement (REL), USB Interface, AUTO/MANUAL range
selection, Auto Power Off and Alarm Buzzer. The instrument adopts the
directly driven 4 digits microprocessor and dual-integral A/D converter, which
provide the high solution and high accuracy digital displaying driver. Because
of its outstanding features, it is an excellent tool and most suitable for lab,
factory, maintenance and repair users.
Open-package Inspection
Open the gift box and take out the instrument, carefully check the follow-
ing accessories. If any accessory was lost or damaged, please contact the
manufactory at once.
• Digital Multimeter 1pc
• Operation Manual 1pc
• Test Lead 1set
• Temperature Cable 1pc
• USB Cable 1pc
• Software disc 1pc
• Transistor test accessory 1pc
Safety Note
The instrument meets the standard of IEC1010 (safety standard promulgated
by the International Electrician Committee). Design and manufacture com-
plied with the standard of Pollution Degree 2.

3
Warning
To avoid endangering the safety of the users, should read the operation
manual carefully before operation, and strictly abide by the safety warning
information and operation description to use the instrument.
1. Caution to avoid the electric shock when measuring the voltage higher
than 30V, the current higher than 10mA, AC Power Lines with Inductive
Load and the AC Power Lines during the period of Electric Power Fluctua-
tion.
2. Before measuring, should check if the function knob is set in the correct
range, make sure the test lead connects reliably, links up correctly, and
insulates properly to avoid the electric shock
3. It meets the requirements of the safety standard only to use the instrument
with the equipped test lead. If the test lead is broken, should replace it by
the same type and same electric specication test lead.
4. Do not replace the inside fuse by the unconrmed one. Only replace it by
the same type and specication fuse. Before replacement, should keep
the test lead off the tested point to make sure there is no any signal at the
input terminal.
5. Do not replace the inside battery by the unconrmed one. Only replace it
by the same type and electric specication battery. Before replacement,
should keep the test lead off the tested point to make sure there is no any
signal at the input terminal.
6. When measuring electricity, do not connect the body with the ground
directly, and do not touch the possible exposed metal terminal, output
socket or lead clamp with ground potential. Usually use the dry cloth, rub-
ber overshoes, rubber cushion and other insulated materials to keep the
body isolated with the ground.
7. Do not store and use the instrument in high humility, high temperature,
combustible, explosive and strong magnetic places.
8. It is possible to damage the instrument and endanger the safety of the
users when measuring the voltage over the range limit. The allowed

4
maximum voltage is printed on the front panel of the instrument, do not
input the range limit specied to avoid the electric shock and instrument
damage
9. Do not measure any voltage when connecting the test lead with the
current terminal to avoid damaging the instrument and endangering the
safety of the users.
10. Do not try to calibrate or repair the instrument, should operate it by the
specially trained or qualied professional people.
11. The function/range selection knob should be set in the correct range
when measuring. When switching the function/range selection knob,
keep the test lead off the tested object to make sure there is no any
signal at the input terminal. Do not switch the function/range selection
knob when measuring.
12. When LCD displays “ ”, please replace the battery in time to make
sure the measuring accuracy.
13. Do not allow to measure the voltage when connecting the test lead with
the current terminal!
14. Do not try to modify the inner circuit at will to avoid damaging the instru-
ment and endangering the safety of the users.
Safety Symbol Description
Warning DCA
High Voltage! Dangerous! ACA
GND DCA & ACA
Dual Insulation Meets the direction of
European IEC
Low Battery Fuse

5
Front Panel Description
1. Instrument Model Number
2. LCD Display
3. HOLD: Date Hold button, press the button, the value is
held on LCD; Press the button again, exit the hold mode
and get into the normal measuring status.
4. HZ/DUTY: Frequency/Duty Circle selection button,
press the button to switch between the Frequency and
Duty Circle mode at Frequency Range; Press the button
to switch to Voltage or Current/Frequency/Duty Circle
model at AC Voltage or AC Current Range.
SELECT: button switch, press the button to switch the
measuring function.
5. MAX/MIN: Maximum, Minimum, press the button, the instrument gets into the MAX
mode, the measuring maximum value will be held at this mode; Press the button
again to get into the MIM mode, the measuring minimum value will be held at this
mode. At the MAX/MIN mode, the maximum or minimum value will be held on
LCD. Under this circumstance, there are no Bar Graph and Auto Power Off function,
hold pressing MAX/MIN button for 2 seconds, exit the MAX/MIN mode.
6. RANGE: Auto Range/ Manual Range switch, the default is set as Auto Range mode
when turning on, press the button and switch to Manual Range. At the Manual Range
mode, press the button once, the range is switched to the higher one, press the but-
ton again to switch the range to the lowest one when measuring the highest range,
the cycle is in proper order from low to high. Keep pressing the button for 2 sec.,
return to Auto Range mode. There is no Auto Range mode at Frequency and Capaci-
tance range.
7. REL: Relative Value Measurement, press the button to the mode of Relative Value
Measurement, press again to cancel the Relative Value Measurement, circulated
like this. Keep pressing the button more than 2 seconds to switch to RS232, RS232
symbol appears on LCD, it indicates the instrument is getting into the status of data
transmission. Keeping pressing the button more than 2 seconds, RS232 symbol
disappears, the data transmission is stopped.
8. Function/range selection knob: select the measuring function and range
9. 10A current input terminal: Measuring AC/DC 10A positive input terminal, insert red
test lead.
10. uA/mA /˚C input terminal: Measuring AC/DC uA/mA and Temperature positive input
terminal.
11. COM input terminal: negative input terminal, insert the black test lead.
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECTRANGE
MAX/MIN
+
-
Ω
A
mA
uA
V
V~
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
1
2
3.1
3.2
3.3
3.6
3.4
3.5
4
5
6
7
8

6
12. VΩHz input terminal: measure Voltage, Frequency/Duty Circle, Resistance, Capaci-
tance, Diode and Continuity positive input terminal, insert the red test lead.
Property
General Feature
1-1 Display: LCD
1-2 Max Display: 5999 (3 5/6) counts automatic polarity display and unit
display.
1-3 Measuring method: dual-integral A/D converter
1-4 Sampling rage: 3 times/second
1-5 Over range indication: display “OL”
1-6 Low battery indication: “ ” appearance
1-7 Operation environment: 0~40˚C relative humidity <80%
1-8 Storage environment: -10~50˚C relative humidity <80%
1-9 Power: 2pcs 1.5V batteries (AAA battery)
1-10 Dimension: 192mm x 95mm x 48mm
1-11 Weight: Approx. 390g (including batteries)
Technic Property
1. Accuracy: (a% × reading + digits) at 23 ± 5˚C , relative humidity <75%.
2. One year calibration guarantee since the time dispatched from the factory.
DC Voltage (DCV)
1. Turn the function/range selection knob to DCV/ACV. Insert the red and
black test lead separately to VΩHz and COM input terminal, press “SE-
LECT” button to switch to DCV measurement mode.
2. The instrument was preset as the Auto Range mode of DCV measure-
ment, displays “AUTO” symbol on LCD, press “RANGE” button to switch
to the Manual Range mode.
3. Connect the test lead to the tested circuit in parallel, the polarity of the red
test lead and the tested voltage value will be displayed on LCD simultane-
ously.

7
Note:
a) Do not measure the voltage higher than DC 1000V or AC 750V.
b) When measuring the high voltage, caution to avoid electric shock. Cut the
connection between the test lead and tested circuit at once after measure-
ment.
C) At the Manual Range mode, if “OL” is displayed on LCD, it indicates the
tested voltage value has exceeded the present range limit, please select
the higher range to complete the measurement.
Range Accuracy Resolution
600mV
±(0.5%+4d)
0.1mV
6V 1mV
60V 10mV
600V 100mV
1000V ±(1.0%+6d) 1V
Input impedance: >60MΩ at Range 600mV , 10MΩ at other range.
Overload protection: 1000V DC or 750V AC peak value.
AC Voltage (ACV)
1. Turn the function/range selection knob to ACV/DCV, press
“SELECT” button to switch to ACV measurement mode. Insert the red and
black test lead separately to VΩHz and VCOM input terminal, displayed
as the following picture.
2. The instrument was preset as the Auto Range mode, displays “AUTO”
symbol on LCD, press “RANGE” button to switch to the Manual Range
mode. Press “Hz/DUTY” button to measure
Frequency/Duty Circle at the Auto Range or
Manual ACA model. But the frequency
response is very low, at this time, it suits
to measure the circuit of high voltage and low
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
SELECT
V
V
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
SELECT
V
V
V~

8
frequency under the circumstance of magnetic
disturbance, such as 220V/50Hz-400Hz,380V/50Hz~400Hz
3. Connect the test lead to the tested circuit
in parallel, the polarity of the red test lead and the tested voltage value will
be displayed on LCD simultaneously
Note:
a) Do not measure the voltage higher than DC 1000V or AC 750V.
b) When measuring the high voltage, caution to avoid electric shock. Cut the
connection between the test lead and tested circuit at once after measure-
ment.
Range Accuracy Resolution
6V
±(0.8%+10d)
1mV
60V 10mV
600V 100mV
750V ±(1.0%+10d) 1V
Input impedance: 10MΩ. Overload protection: 1000V DC or 750V AC peak
value. Frequency response: 40-400Hz. Indication: average value response
(RMS of sine wave). Duty Circle indication (0.1%-99.9%)
DC Current (DCA)
1. Insert the black test lead to “COM” input terminal and the red test lead to
“uAmA ”or “10A”, displayed as the right picture.
2. Turn the function/range selection knob to current range, press “SELECT”,
switch to DC measurement mode, then connect the test lead with the
tested circuit in series, the polarity of the red test lead and the tested cur-
rent value will be displayed on LCD simultaneously.
3. If “OL” is displayed on LCD, it indicates the test current value has exceed-
ed the present range limit, please select the higher range to complete the
measurement.

9
Note:
a) Do not measure the current higher than 10A at Range 10A and higher
than 6000uA at uA Range and higher than 600mA
at mA Range, otherwise the fuse will be
burnt out or the instrument will be damaged.
b) Do not connect the test lead to any circuit
in parallel when the test lead is inserted in
the current input terminal, otherwise it is
possible to damage the instrument or
endanger the safety of the users. Cut
the connection between the test lead
and tested circuit at once after measurement.
Range Accuracy Resolution
600uA
±(1.0%+10)
0.1μA
6000uA 1μA
60mA 10μA
600mA 100μA
6A ±(1.2%+10) 1mA
10A 10mA
Max input current: 10A (less than 15 seconds).
Overload protection: 0.5A/250V fuse, 10A/250V fuse.
AC Current (ACA)
1. Insert the black test lead to “COM” input terminal and the red test lead to
“uAmA ”or “10A”input terminal,displayed as the right picture.
2. Turn the function/range selection knob to current range, press “SELECT”,
switch to AC measurement mode, then connect the test lead to the tested
circuit in series, the polarity of the red test lead and the tested current
value will be displayed on LCD simultaneously.
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
µA
V
µA
DC
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
V
DC
SELECT
SELECT
10A
A

10
3. If “OL” is displayed on LCD, it indicates the tested current value has
exceeded the present range limit, please select the higher range to com-
plete the measurement.
Note:
a) Do not measure the current higher than 10A at Range 10A and higher
than 600mA at mA Range
b) Do not connect the test lead to any circuit in parallel when the test lead is
inserted in the current input terminal, otherwise it is possible to damage
the instrument or endanger the safety of the users. Cut the connection
between the test lead and tested circuit at once after measurement.
Range Accuracy Resolution
600uA
±(1.5%+10d)
0.1μA
6000uA 1μA
60mA 10μA
600mA 100μA
6A ±(2.0%+15d) 1mA
10A 10mA
Max input current: 10A (less than 15 seconds). Overload protection:0.5A/
250V fuse, 10A/250V fuse.
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
mA
V
mA
DC
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
10A
V
A
DC
SELECT SELECT

11
Frequency response: 40-100Hz.
Duty Circle Indication: (0.1%-99.9%)
Resistance (Ω)
1. Turn the function/range selection knob to Ω, insert the red and black test
lead separately to VΩHz and COM input terminal.
2. Connect the test lead to the tested resistance in parallel, the tested resis-
tance value will be displayed on LCD
3. Auto Range mode is preset when turning on, press “RANGE” button to
switch to Manual Range mode.
4. If “OL” is displayed on LCD, it indicates the tested resistance value has
exceeded the present range limit, please select the higher range to com-
plete the measurement.
Note:
a) When measuring the in-circuit resistance, Make sure all the power of the
tested circuit has been turned off and all capacitors are fully discharged.
b) It will cause the reading incorrect to input any voltage when measuring the
resistance. If the voltage exceeds 250V, over-range protection voltage,
it is possible to damage the instrument and endanger the safety of the
users.
c) At Range 600Ω, short-circuit the test lead to measure the wire resistance,
and then subtract it from the real measurement.
Range Accuracy Resolution
600Ω ±(0.8%+5d) 0.1Ω
6kΩ
±(0.8%+4d)
1Ω
60kΩ 10Ω
600kΩ 100Ω
6MΩ 1kΩ
60MΩ ±(1.2%+10d) 10kΩ
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
V
RANGE
Ω

12
Open circuit voltage: 400mV.
Over range protection: 250V AC/DC peak value.
Diode and Continuity Test
1. Turn the function/range selection knob to “ ”Range, displayed as the
right pictures.
2. Insert the red and black test lead separately to VΩHz and COM input
terminal. Press “SELECT” button to choose the Buzzer and Diode mea-
surement function.
3. Connect the RED test lead to the positive pole of the tested diode, BLACK
test lead to the negative pole.
4. Read the present test result from LCD. (Note: no Bar Graph display at
Diode Range)
Note:
a) If the diode is open circuit or the polarity is connected counter, “OL” will be
displayed on LCD.
b) When measuring the in-circuit diode, make sure all the power of the
tested circuit has been turned off and all capacitors are fully discharged.
c) Cut the connection between the test lead and tested circuit at once after
measurement.
Range Display Test Condition
Diode Forward voltage
drop
Forward AC Current: 1.0mA, Counter
Voltage: 3.0V
Buzzer sound at less
than 50Ω
Open Voltage: 0.5V
Overload protection: 250V DC/AC peak value.
Warning: Do not input the voltage at the range for safety.
Capacitance (C)
1. Turn the function/range selection knob to Capacitance Range. Insert the

13
red and black test lead separately to VΩHz and COM input terminal.
2. Connect the test lead to the tested capacitor in parallel, the tested capaci-
tor value will be displayed on LCD.
3. If “OL” is displayed on LCD, it indicates the test capacitor value has
exceeded the present range limit or the capacitor is short-circuit, please
select the higher range to complete the measurement.
4. Read the present test result from LCD.
Note:
a) When measuring the in-circuit capacitor, make sure all the power of the
tested circuit has been turned off and all capacitors are fully discharged.
(Note: no Bar Graph display at this range)
b) It requires longer testing time when measuring the large capacitor, it takes
about 15 seconds at Range 100uF.
c) Cut the connection between the test lead and tested circuit at once after
measurement.
Range Accuracy Resolution
40nF ±(5.0%+30d) 10pF
400nF
±(3.5%+8d)
100pF
4μF 1nF
40μF 10nF
200μF ±(5.0%+10d) 100nF
Overload protection: 250V DC/AC peak value.
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
V
SELECT
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
V
SELECT
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
V
REL/RS232
+ -
4.7µF
25V

14
Frequency (Hz)
1. Turn the function/range selection knob to Hz Range. Insert
the red and black test lead separately to VΩHz and COM input terminal.
2. Connect the test lead to the tested signal source in parallel, Read the
present test result from LCD. (Note: no Bar Graph display at this range)
3. When measuring Frequency, press “Hz/DUTY” button once to get into
the mode of DUTY measurement, and press “Hz/DUTY” button again to
return to the mode of Frequency measurement.
4. When measuring AC current or voltage, press “Hz/DUTY” button to get
into the mode of Frequency measurement, and press “Hz/DUTY” button
again to get into the mode of Duty Circle measurement, and press the
button third to return to the mode of AC current or voltage measurement.
Note:
a) Do not input the signal more than 60V. Otherwise it is possible to damage
the instrument and endanger the safety of the users.
b) Cut the connection between the test lead and
c) tested circuit at once after measurement.
Range Accuracy Resolution
100Hz
±(0.5%+4d)
0.01Hz
1000Hz 1Hz
10kHz 10Hz
100kHz 100Hz
1MHz 1kHz
20MHz 10kHz
Input sensitivity: 1.0V.
Overload protection: 250V DC/AC peak value.
Duty Circle Indication: (0.1%-99.9%)
Transistor Test
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
Hz/DUTY
V
V~
y
X
60Hz
VΩHz
CAT ll
10A
COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
Ω
A
mA
uA
hEF
Hz ˚C
OFF
MT-1820
AUTO POWER OFF
V
hEF

15
1. Turn the function/range selection knob to “HFE” Range, displayed as the
right picture.
2. Insert the accessory of Transistor test into the “uAmA ”
3. and “COM” input terminal, displayed as the picture.According to the model
of the tested transistor, insert the accessory accordingly into the terminal
of “EBC” of “NPN” or “PNP”.
4. Read the present test result from LCD.
Note:
a) Do not input the current or voltage at the input terminal of “uAmA ”, “COM”
or transistor accessory, otherwise it is possible to damage the instrument
or endanger the safety of the users.
b) There are no Data Hold, MAX/MIN, Bar Graph function at Transistor Test
mode.
Range Scope of Display Test Condition
HFE(NPNorPNP) 0-1000 Base Current:1mA VCE:2.1V
Temperature Test
1. Turn the function/range selection knob to
Temperature Range.
2. Insert the two ends of the temperature sensor
Into the “COM” and “uAmA” input terminal, the
positive end into the “uAmA” input terminal.
3. Connect the sensor of the temperature cable
to the surface or inside of the tested object,
displayed as the right picture.
4. Read the present test result from LCD.
5. Press “SELECT” button to choose F temperature measurement mode,
and press “SELECT” button again to choose C temperature measurement
mode, circulated like this.
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
SELECT
V

16
Note:
a) Without the signal input, LCD automatically displays the normal tempera-
ture.
b) Do not replace the temperature sensor at will. Otherwise the accuracy
can’t be assured.
c) Do not input the voltage at Temperature Range, caution to avoid damag-
ing the instrument.
Range Accuracy Resolution
-20˚C~400˚C ±(1.0%+50) 0.1˚C
400˚C~1000˚C ±(1.5%+15) 1˚C
0˚F~750˚F ±(1.0%+50d) 1˚F
750˚F~1832˚F ±(1.5%+5d)
Overload protection: 0.5A/250V
Other Functions and Instrument Maintenance
• Other Functions
1. Date Hold
Press “HOLD” button, the present value is held on LCD; Press the button
again, exit the hold mode and get in the normal measuring status.
2. Auto Power Off
Stop working for 15 seconds, the instrument will auto
power off, and get into the sleeping mode. The buzzer inside will sound 5
times one minute before powering off, there is a long sound one minute
later and the instrument gets into the sleeping mode. Press any key to
restart the power.
3. Ress “REL/RS232”button to get into the Relative Value Measurement
mode, Keep holding “REL/RS232” button more than 2 seconds, RS232
symbol is displayed on LCD, it indicates it is the status of the instrument
connecting with PC, then connect the instrument to PC by USB Cable,
VΩHz
CAT ll
10A
uAmA COM
MAX 10A
10sec
FUSED
MAX 400mA
FUSED
MAX
1000V DC
750V AC
REL/RS232
Hz/DUTY HOLD
SELECT RANGE
MAX/MIN
+
-
Ω
A
mA
uA
hEF
Hz ˚C
˚C
OFF
MT-1820
AUTO POWER OFF
hEF
SELECT
V

17
accessory of the instrument, and then can transmit the measuring data to
PC, it is convenient to record, analyze, process and print the measuring
results, etc.
Please refer the details to the description in the software.
• Instrument Maintenance
This is a highly precise instrument, do not try to modify the inner circuit at
will.
1. Keep the instrument dry, and keep it away form dust and shock.
2. Do not store and use the instrument in high humility, high temperature,
combustible, explosive and strong magnetic places.
3. Clean the surface of the instrument with the damp cloth and gentle deter-
gent, do not use the strong solvent like the abrasive cleaner and alcohol,
etc.
4. Take out the batteries if do not use the instrument for a long time to pre-
vent the batteries from leaking the liquid to corrode the instrument.
5. When LCD displays “ “ symbol, should replace the batteries as the
following steps:
5-1. Loose the screw that xes the batteries, and remove the battery case.
5-2. Remove the spent 1.5V batteries, and replace them by two same type
new batteries. It is better to use alkaline batteries for lengthening the
usage time.
5-3. Fit on the battery case and tighten the screw.
5-4. The steps of replacing the fuse are same as the above. When replacing
the fuse, please use the same specication, same type of fuse.
Note:
1. Do not input the voltage more than 1000V DC/AC peak value.
2. Do not measure the voltage at the Current, Resistance, Diode and Buzzer
Range.
3. Do not use this instrument to measure before xing the battery or tighten-
ing the bottom case.

18
4. Please remove the test lead from the tested point and turn the power off
before replacing the battery or fuse.
The instruction manual is subject to chance without notice.
The contents in the instruction manual are considered to be correct, if the us-
ers nd any errors or pretermission, etc., please contact the manufacturer.
The manufacturer hereby will not be responsible for any accident and dam-
age caused by the improper operation.
The functions described in this instruction manual do not be the reason for
special usage.

19
目 錄
概述 20
開箱檢查 20
安全注意事項 20
安全符號說明 22
儀錶面板及按鍵功能說明 22
其他功能 23
特性 23
直流電壓(DCV) 24
交流電壓(ACV) 25
直流電流(DCA) 25
交流電流(ACA) 27
電阻 28
二極體及通斷測試 29
電容(C) 30
頻率(Hz) 30
三極管測量及溫度測量 31
溫度測量 32
通訊連接 32
儀錶保養 33