Major tech MT873 User manual

Range Resolution Accuracy
600μA 0.1μA
6000μA 1μA
60mA 10μA
600mA 100μA
±(1.2% of rdg + 2 digits)
6A 1mA
10A 10mA ±(2.0% of rdg + 3 digits)
Range Resolution Accuracy
6V 1mV
60V 10mV ±(1.0% of rdg + 3 digits)
600V 100mV ±(1.5% of rdg + 3 digits)
Range Resolution Accuracy
600mV 0.1mV
6V 1mV
60V 10mV
±(0.5% of rdg + 2 digits)
600V 100mV ±(0.8% of rdg + 2 digits)
MT873
Digital Multimeter
Introduction
The MT873 multimeter is a slim sized, portable, robust drop proof digital multimeter. The
MT873 has a 6000 count digit LCD monitor with large 25mm digits that offer clear and
easy reading. The circuitry design is centred on large-scale IC A/D converters in
conjunction with an over-load protection circuit, the meters offers excellent performance
and is ideal for a versatile digital multimeter.
The meters can be used to measure DC & AC voltage, DC & AC current, resistance,
capacitor, frequency, duty cycle, temperature, Non Contact AC Voltage (NCV) detection,
diode test and audible continuity. If the equipment is used in a manner not specified by
the manufacturer, the protection provided by the equipment may be impaired.
This Equipment Conforms to UL STD. 61010-1, 61010-2-030 and 61010-2-033; Certified to
CSA STD. C22.2 NO. 61010-1, 61010-2-030 and 61010-2-033.
1. CDS sensor: The CDS sensor can reaction to the ambient brightness range, then
automatically control the LCD backlight to lighten or go out.
2. NCV detection area: Non Contact AC Voltage (NCV) detection area.
3. NCV red light: Non Contact AC Voltage (NCV) detection red light.
4. NCV green light: Non Contact AC Voltage (NCV) detection green light.
5. LCD display: 6000 counts digit, full function symbol display.
6. SELECT key: This key work on the “ ” range, press the key to c hoose resistance, .
diode or continuity test, on the voltage or current range, change to DC or AC, on the
°C/°F range, change to °C or °F test; I f press a nd hold SELECT key to power on, “Auto
Power Off ” function will be disabled.
7. RANGE Key: Press the “RANGE” key, the meter enters manual range mode, press it
more than 2 seconds again, return to auto mode.
8. HOLD key: Press the “HOLD” key to lock display value, and the “DH” sign w ill appear
on the display, press it again to exit.
9. REL Key: Press the “REL” key, the meter enters relative measuring mode, “REL” is
displayed on the LCD and the present reading becomes the reference value and
displayed on the display. Relative measurement REL =measurement value-Reference
value. Press it again to exit.
10. Hz/% Key: On “ACV/ACA” or “Hz” range, press the “Hz/%” key, you can choose the
Frequency or Duty Cycle measurement.
11. Rotary Switch: Use this switch to select functions and ranges.
12. COM: COM and Temperature “-” Input Jack.
13. 10A: 10A Input Jack
14. VΩmA: V/μAmA/Hz/Ω / and Temperature “+” Input Jack
15. Meter casing
16. Protective casing
Safety Information
1. The meter is designed according to IEC-61010 concerning e lectronic m easuring
instruments with an over-voltage category 600V (CAT II) or 300V (CAT III) and
pollution 2.
2. Follow all safety and operating instructions to ensure that the m eter is u sed safely and
is kept in good operating condition.
3. Safety symbols:
Important safety information, refer to the operating manual.
Dangerous voltage may be presence
Double insulation (protection Class II)
Special Cautions for Operation
1. The meters can be safe only according to standard procedures w hen used i n conjunction
with the supplied test leads. Please replace damaged test leads with the same
specifications.
2. To avoid risk of electric shock, do not use the meter if the casing h as been o pened.
3. The range switch should be in the right position before making a m easurement.
4. To avoid electric shock and damaging the instrument, the input s ignals must n ot exceed
the specified limits.
5. When measuring TV set or switched power, attention should be p aid to the p ossible pulses
that may cause damage to the circuitry.
6. Range switch position must not be changed at random during m easurement.
7. Take caution against shock in the course of measuring voltage h igher than D C 60V & AC
30V.
8. Protection fuse should be replaced only with same type and same s pecification.
9. After using the meter, set function switch to OFF to save battery p ower.
10. If the meter is not used for a long time, take out battery to avoid d amage b y battery
leakage.
General Specifications
1. Max Voltage between input terminal and Earth: CAT II 600V or CAT III 300V
2. Over-range Indication: display “OL” for the significant digit.
3. Automatic display of negative polarity “-”.
4. Low Battery Indication: “ ” displayed..
5. Max LCD display: 6000 counts digit.
6. Auto range & Manual range control
7. Auto Power Off: When measurement exceeds 15 minutes without c hanging t he mode and
pressing key, the meter will switch to standby mode. Press any key to exit standby mode.
When switching the meter back on, press and hold the SELECT key to disable auto power
off.
8. Auto LCD backlight
9. Fuse protection: 600mA/600V Fast Fuse, 10A/600V Fast Fuse
10. Power supply: 9V 6F22 battery
11. Operating Temp.: 0 to 40 (relative humidity <85%)°C °C
12. Storage Temp.: -10 to 50 (relative humidity <85%)°C °C
13. Guaranteed precision Temp.: 23±5 (relative humidity <70%)°C
14. Dimension: 150 x 100 x 36mm
15. Weight: approx. 250g (including battery)
Testing Specifications
Accuracy is specified for a period of year after calibration and at 18 to 28 (64 to 82 ) °C °C °F °F
with relative humidity to 70%.
DC Voltage
* Impedance: 10MΩ, More than 100MΩ on 600mV range
* Overload protection: 600V DC or AC RMS
AC Voltage (True RMS)
* Impedance: 10MΩ
* Overload protection: 600V DC or AC RMS
* Frequency Range: 40 to 400Hz
DC Current
* Overload protection: 600mA/600V Fast Fuse, 10A/600V Fast Fuse,
10A up to 10 seconds
Panel Layout
Resistance
Range Resolution Accuracy
600Ω 0.1Ω ±(1.0% of rdg + 3 digits)
6kΩ 1Ω
60kΩ 10Ω
600kΩ 100Ω
6MΩ 1kΩ
±(1.0% of rdg + 2 digits)
60MΩ 10kΩ ±(1.5% of rdg + 3 digits)
Range Resolution Accuracy
600μA 0.1μA
6000μA 1μA
60mA 10μA
600mA 100μA
±(1.5% of rdg + 3 digits)
6A 1mA
10A 10mA ±(2.5% of rdg + 5 digits)
AC Current (True RMS)
* Overload protection: 600mA/600V Fast Fuse, 10A/600V Fast Fuse,
10A up to 10 seconds
* Frequency Range: 40 to 400Hz
* Overload protection: 600V DC or AC RMS
1
4
9
10
14
15
16
2
3
5
6
7
8
11
12
13

Frequency
Range Accuracy Resolution
9.999Hz 0.001Hz
99.99Hz 0.01Hz
999.9Hz 0.1Hz
9.999kHz 1Hz
99.99kHz 10Hz
999.9kHz 100Hz
9.999MHz
± (0.1% of rdg + 5 digits)
1kHz
* Sensitivity: sine wave 0.6V rms (9.999MHz: 1.5V RMS)
* Overload protection: 600V DC or AC RMS
Duty cycle
0.1%～99.9%: ± ( 2.0% of rdg + 2 digits ), Frequency lower than 10kHz
* Sensitivity: sine wave 0.6V RMS
* Overload protection: 600V DC or AC RMS
Temperature
Range Accuracy Resolution
-20~150°C
°C 150~1000°C 1 °C
-4~302°F
°F 302~1832 F °
± ( 3 + 1digit ) °C
± ( 3% of rdg + 2digits )
± ( 5 + 2digits ) °F
± ( 3% of rdg + 3digits ) 1°F
* NiCr-NiSi Type-K sensor
* Overload protection: 600mA/600V Fast Fuse
Diode and Audible continuity test
Range Description Test Condition
Display read approximately
forward voltage of diode
Forward DC current
approx. 1.5mA
Reversed DC voltage
approx. 4V
Built-in buzzer sounds if
resistance is less than 50Ω
Open circuit voltage
approx. 2V
* Overload protection: 600V DC or AC RMS
Operating Instructions
Attention before operation
1. Check battery. When the battery voltage drops below proper operation r ange, the “ ”
symbol will appear on the LCD display and the battery needs to be replaced.
2. Pay attention to the “ ” besides the input jack which shows that the i nput voltage or .
current should be within the specified value.
3. The range switch should be positioned to desired range for measurement b efore
operation.
Measuring DC & AC Voltage
1. Connect the black test lead to COM jack and the red to VΩmA jack.
2. Set the rotary switch at the desired “V ” range position, it shows symbol for testing .
DC voltage, if you want to test AC voltage, push “SELECT” button switch.
3. Connect test leads across the source or load under measurement.
4. You can get the voltage reading from LCD. The polarity of the red lead connection will
be indicated along with the DC voltage value.
Note:
1. “ ” means you can't input the voltage more than 600V, it's p ossible to s how higher .
voltage, but it may damage the inner circuit or cause a shock.
2. Be cautious against shock when measuring high Voltage.
Measuring DC & AC Current
1. Connect the black test lead to COM jack and the red to the V ΩmA jack for a maximum
600mA current , for a maximum 6A or 10A current, move the red lead to the 10A jack.
2. Set the rotary switch at the desired “uA ” & “mA ” & “A ” range position, it . . .
shows symbol for testing DC current, if you want to test AC current, push “SELECT”
button switch.
3. Connect test leads in series with the load under measurement.
4. You can get the amperage reading from LCD. The polarity of the red lead connection
will be indicated along with the DC current value.
Note:
1. When the value scale to be measured is unknown beforehand, set t he range selector at
the highest position.
2. When only “OL” is displayed, it indicates over-range situation and the higher range has
to be selected.
3. “ ” means the socket mA's maximum current is 600mA and 10A's maximum current is .
10A, over 600mA or 10A current can be protected by the fast fuse.
4. On the 10A range, the measuring time should be less than 10 seconds to prevent
precision from affecting by circuit heating.
Measuring Resistance
1. Connect the black test lead to COM jack and the red to VΩmA jack.
2. Set the rotary switch at the desired “Ω ” range position..
3. Connect test leads across the resistance under measurement.
4. You can get the resistance reading from LCD.
Non Contact AC Voltage (NCV) detection
Test voltage range: 90V～1000V AC RMS
The NCV red light and green light will light up alternately together with sound
Note: Max. input overload: 600V rms＜10sec
1. For measuring resistance above 1MΩ, the meter may take a few s econds to stabilize.
2. When the input is not connected, i.e. at open circuit, the figure ' OL' will be displayed for
the over-range condition.
3. When checking in-circuit resistance, be sure the circuit under test h as all power removed
and that all capacitors have been discharged fully.
Measuring Capacitance
1. Connect the black test lead to COM jack and the red to VΩmA
jack.
2. Set the rotary switch at the desired “Ω ” range position..
3. Connect test leads across the capacitance under measurement.
4. You can get the capacitance reading from LCD.
Note: Max. input overload: 600V rms＜10sec
1. Capacitors should be discharged before being tested.
2. When testing large capacitance, it will take longer time before the f inal value is
measured (For 100uF~99.99mF range, it will take about 10 seconds).
3. When testing small capacitance (≤1uF), to assure the measurement accuracy, first press
“REL”, then go on measuring.
Measuring Frequency & Duty cycle
1. Connect the black test lead to COM jack and the red to VΩmA jack.
2. Set the rotary switch at the desired “Hz” range position.
3. Push “Hz/%” key to choose Frequency or Duty cycle test.
4. Connect the probe across the source or load under measurement.
5. You can get the frequency reading from LCD.
Measuring Temperature
1. Connect the black banana plug of the sensor to COM jack and the r ed banana plug to
the VΩmA jack.
2. Set the rotary switch at the desired °C/°F range position, push “SELECT” to choose °C
°F or measurement.
3. Put the sensor probe into the temperature field under measurement.
4. You can get the temperature reading from LCD.
Note:
1. The accessory of the meter type contact thermocouple limited temperature is 250°C,
please use special probe for testing higher temperature.
2. Please don't change the thermocouple at will, otherwise we can't guarantee to measure
accuracy.
3. Please don't measure voltage in the temperature function.
Diode & Audible continuity Testing
1. Connect the black test lead to COM jack and the red to VΩmA jack.
2. Set the rotary switch at the “Ω ” range position, push “SELECT” to choose Diode .
or Audible continuity measurement.
3. On diode range, connect the test leads across the diode under measurement, display
shows the approx. forward bias voltage of this diode.
4. On Audible continuity range, connect the test leads to two point of circuit, if the
resistance is lower than approx. 50Ω, the buzzer sounds.
Note: Make sure the power is removed and all capacitors need to be discharged under this
measurement.
Non-Contact AC Voltage detection
1. Set the rotary switch at the desired “NCV” range position, the NCV green LED light will
light up.
2. Hold the Meter so that the meter's top is vertically and horizontally centred with the
conductor, when the live voltage ≥ 90V AC rms, the NCV red LED light and green LED
light will light up alternately together with sound.
Note:
1. Even without LED indication, the voltage may still exist. Do not rely on non-contact
voltage detector to determine the presence of voltage wire. Detection operation may be
subject to socket design, insulation thickness and different type and other factors.
2. When the meter measures voltage, due to the influence of presence of voltage, the
voltage sensing indicator may also light up.
3. Keep the meter away from electrical noise sources during the tests, i.e., florescent lights,
dimmable lights, motors, etc.. These sources can trigger Non-Contact AC Voltage
detection function and invalidate the test.
Battery replacement
1. When the battery voltage drops below proper operation range the “ ”symbol will .
appear on the LCD display and the battery needs to be replaced.
2. Before replacing the battery, set the selector switch to “OFF” position and remove the
test leads from the terminals. Open the cover of the battery cabinet with a suitable
screwdriver.
3. Replace the old battery with the same type battery (9V 6F22).
4. Close the cover of the battery cabinet and fasten the screw.
Fuse replacement
1. This meter is provided with a 600mA/600V fast fuse to protect the battery test,
temperature test and the current measuring circuits which measure up to 600mA, with a
10A/600V fuse to protect the 10A range.
2. Ensure the meter is not connected to any external circuit, set the selector switch to
“OFF” position and remove the test leads from the terminals. Open the cover of the
battery cabinet with a suitable screwdriver.
3. Replace the old fuse with the same type and rating: 6×32mm 600mA/600V fast fuse or
6×32mm 10A/600V fast fuse.
4. Close the cover of the battery cabinet and fasten the screw.
Maintenance
1. You must replace the test leads if the insulation is broken and the internal wire exposed.
exposed, use the same test leads with the same specifications same specifications.
2. Use only moist fabric or small amount of detergent but not chemical solution for
cleaning.
3. Do not use the meter before the back cover is properly closed and screw secured. Upon
any sign of damage, stop operation immediately and send the meter for maintenance.
4. Please take out the battery when not using for a long time.
Accessories
1. Test Leads: electric rating 600V 10A. If the test leads need to be replaced, you must use
a new one which should meet EN 61010-031 standard, rated CATIII 600V, 10A or better.
2. “K” type thermocouple sensor probe
3. Operator's Manual
Capacitance
* Overload protection: 600V DC or AC RMS
Range Accuracy Resolution
9.999nF ±(3.0% of rdg + 10 digits) 1pF
99.99nF 10pF
999.9nF 100pF
9.999µF
±(2.5% of rdg + 5 digits)
1nF
99.99µF ±(5.0% of rdg + 10 digits) 10nF
999.9µF 100nF
9.999mF 1µF
99.99mF
±(10.0% of rdg + 20 digits)
10µF
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