Major tech MT1875 User manual

MT1875
6-in-1 Environmental
Multimeter
INSTRUCTION MANUAL

Contents Page no
1. Introduction............................................................................3
2. Safety Instructions..................................................................3
3. Panel Descriptions.................................................................4
4. Features...................................................................................5
5. Specifications.........................................................................6
5.1. General Specifications.......................................................6
5.2. Sound Level.......................................................................6
5.3. Light...................................................................................6
5.4. Temperature/Humidity....................................................... 7
5.5. Multimeter..........................................................................7
6. Operating Instructions........................................................... 9
6.1. Measuring Sound Level..................................................... 9
6.2. Measuring Humidity...........................................................9
6.3. Measuring Light................................................................10
6.4. Measuring Temperature...................................................11
6.5 .Measuring DC Voltage.....................................................11
6.6. Measuring AC Voltage......................................................12
6.7. Measuring DC Current......................................................12
6.8. Measuring AC Current......................................................12
6.9. Measuring Capacitance...................................................13
6.10. Measuring Frequency.....................................................13
6.11. Measuring Resistance....................................................13
6.12. Measuring Diode............................................................14
6.13. Audible Continuity Test...................................................14
6.14. Non-Contact AC Voltage Test.........................................14

1. Introduction
The 6-in-1 environmental multimeter has been designed to combine the
functions of a Sound Level Meter, Light Meter, Humidity Meter,
Temperature Meter, Non-Contact AC Voltage Tester and a Digital
Multimeter.
The Sound Level function can be used to measure noise in factories,
schools, offices, airports, home, etc., checking acoustics of studios,
auditoriums and hi-fi installations. The Light Level function is used to
measure illuminance in the field. It is fully cosine corrected for the
angular incidence of light. The light sensitive component used in the
meter is a stable, long life silicon diode.
The Temperature is for use as a semiconductor sensor and Type-K
thermocouple. The digital multimeter performs AC/DC Voltage, AC/DC
Current, Resistance measurement and Audible Continuity, Diode,
Temperature test.
2. Safety Instructions
This meter has been designed for safe use, but must be operated with
caution. The rules listed below must be carefully followed for safe
operation.
NEVER apply voltage or current to the meter that exceeds the specified
maximum.
Input Protection Limits
Function
VDC or VAC
mA AC/DC
A AC/DC
Frequency, Resistance,
Capacitance, Duty Cycle,
Diode Test, Continuity
Temperature
Maximum Input
600V DC/AC RMS
500mA 660V fast acting fuse (500mA/660V)
10A 600V fast acting fuse (10A for 30
seconds max every 15 minutes)
600V DC/AC RMS
600V DC/AC RMS
Indicates operators must refer to the explanation in this manual.
Indicates terminals at which dangerous voltage maybe present.
3

3. Panel Description
1. Humidity & Temperature - Humidity Sensor and Semiconductor
sensor inside for indoor.
2. LCD display - 4000 count LCD display.
3. Function switch
4. V / Hz% / Ω / CAP / °C input jack
5. COM input jack
6. μA / mA input jack
7. 10A input jack
8. Microphone - Electric condenser microphone inside.
9. Photo Detector - Long life silicon photo diode inside.
10. Hz/% button - The button at AC/DC Voltage measurement and
AC/DC Current measurement and Hz%
measurement Function is availability.
11. Hold/Backlight button - Press the HOLD button to “freeze” the
reading on the display. The “HOLD”
message will appear on the display. Hold
the backlight button to turn the LCD light
ON or OFF.
1
2
16
10
11
12
3
4
56
7
15
14
13
8
9
ROOM
3
4

12. Ambient Temp °C/°F - Press the ambient temperature button to
display temperature on screen in °C or °F
13. MODE button - To select AC or DC measurement when in A, mA,
uA, and Ω, , ranges.
14. RANGE button - To select AC or DC measurement when in Voltage,
Ω ranges.
15. REL button
• The relative measurement feature allows you to make
measurements relative to a stored reference value. A reference
voltage, current, capacitor, etc. can be stored and measurements
made in comparison to that value. The displayed value is the
difference between the reference value and the measured value.
• Perform the measurement as described in the instructions.
• Press the REL button to store the reading in the display and the
“REL“ indicator will appear on the display.
• The display will now indicate the difference between the stored
value and the measured value.
• Press the REL button to exit the relative mode.
16. NCV indicate lamp
4. Features
• 14 functions measure Sound level, Light, Humidity, Temperature,
DC Voltage, AC Voltage, DC Current, AC Current, Resistance, Diode
and Continuity test.
• 4000 count large LCD display with units of Lux, °C, %RH and dB
indication.
• Easy to use with single function switch operating, compact and light
weight.
• Sound level measures from 35dB to 100dB for C weighting checking
with 0.1dB resolution.
• Light measuring levers ranging from 1 Lux to 40,000 Lux.
• Humidity measurement from 30%RH to 90%RH with 1%RH
resolution and fast time response.
5

5. Specifications
5.1. General Specifications
Display: 4000 counts LCD display with function of Lux,
°C, % and dB indication.
Polarity: Automatic, ( - ) negative polarity indication.
Over-range: “OL” mark indication.
Low battery indication: The “ ” is displayed when the battery
voltage drops below the operating level.
Measurement rate: 3 times per second, nominal.
Operating environment: 0°C to 40°C (32°F to 104°F) at <70%RH
Storage temperature: -10°C to 60°C (14°F to 140°F) at <80%RH
Battery: 9V
Dimensions: 170 x 78 x 48mm
Weight: 335g including holster
Accuracy is given at 18°C to 28°C (65°F to 83°F), less than 70%RH.
5.2. Sound Level
Measurement range: 35 to 100dB
Resolution: 0.1dB
Frequency Range: 30Hz to 10kHz
Frequency Weighting: C – weighting
Time Weighting: Fast
Accuracy: ±5dB at 94dB sound level, 1kHz sine wave.
Microphone: Electric condenser microphone.
5.3. Light Level
Measurement range: 4000, 40,000Lux
(40,000Lux range reading x 10)
Overrate Display: Highest digit of “OL” is displayed.
Accuracy: ±(5% rdg +10 dgts) calibrated to standard
incandescent lamp at colour temperature
2856k).
Repeatability: ±2%
Temperature Characteristic: ±0.1% / °C
Photo Detector: One silicon photo diode with filter.
6

5.4. Temperature/Humidity
Range
-20°C to 750°C
-4°F to 1382°F
Accuracy
±(3% + 5 digits)
±(3% + 9 digits)
Function
Temperature
Type-K
Resolution
1°C
1°F
Input Impedance: 10MΩ
Overload Protection: 250V DC or AC RMS for 400mV ranges and 250V DC or 250V
AC RMS for other ranges.
Range
0°C to 50°C
Accuracy
±(3% + 5 digits)
Function
Indoor Temperature
Resolution
0.1°C
Range
33% to 99% RH
Accuracy
±(3% + 5 digits)
Function
Indoor Humidity
Resolution
1%RH
Input Impedance: 10MΩ
Overload Protection: 250V DC or AC RMS for 400mV ranges and 250V DC or 250V
AC RMS for other ranges.
400.0mV
4.000V
40.00V
400.0V
600V
±(1% + 4 digits)
±(1.5% + 4 digits)
DC Voltage
(Auto-Ranging)
Range
Accuracy
Function Resolution
0.1mV
1.0mV
10mV
100mV
1V
Input Impedance: 10MΩ
Overload Protection: 600V DC or AC RMS for 400mV range and 600V DC or 600V
AC RMS for other ranges.
5.5. Multimeter
7
400.0mV
4.000V
40.00V
400.0V
600V
±(1.5% ± 15 digits)
±(1.5% ± 4 digits)
AC Voltage
(Auto-Ranging
Except 400mV)
Range
Accuracy
Function Resolution
0.1mV
1.0mV
10mV
100mV
1V
Input Impedance: 10MΩ
Frequency Range: 50 to 400Hz
Maximum Input: 600V DC or 600V AC RMS
±(1% ± 4 digits)
±(2% ± 4 digits)

400.0uA
4000uA
400.0mA
10A
±(1% ± 2 digits)
±(2% ± 5 digits)
DC Current
(Auto-Ranging for
uA and mA)
Range
Accuracy
Function Resolution
0.1uA
1uA
100uA
10mA
Overload Protection: 500mA/660V and 10A/600V Fuse
Maximum Input: 400mA DC or 400mA AC RMS on uA/mA ranges, 10A DC or AC
RMS on 10A range.
±(1% ± 2 digits)
±(1.2% ± 2 digits)
400.0uA
4000uA
400.0mA
10A
±(1.2% ± 2 digits)
±(2% ± 5 digits)
AC Current
(Auto-Ranging for
uA and mA)
Range
Accuracy
Function Resolution
0.1uA
1uA
100uA
10mA
Overload Protection: 500mA/660V and 10A/600V Fuse
AC Response: 50Hz to 400Hz
Maximum Input: 400mA DC or 400mA AC RMS on uA/mA ranges, 10A DC or AC
RMS on 10A range.
±(1.2% ± 2 digits)
±(1.5% ± 2 digits)
400.0Ω
4.000kΩ
40.00kΩ
400.0kΩ
±(1.5% ± 4 digits)
Resistance
Range
Accuracy
Function Resolution
0.1Ω
1Ω
10Ω
100Ω
Overload Protection: 15 seconds maximum 250V DC or 250V AC RMS, on all
ranges.
Maximum Open Circuit Voltage: 2.8V
±(1.5% ± 2 digits)
4.000MΩ
40.00MΩ±(2.5% ± 2 digits)
10kΩ
1MΩ
±(2% ± 2 digits)
8
50.00nF
500.0nF
5.000uF
50.00uF
±(5% ± 7 digits)
Capacitance
(Auto-ranging)
Range
Accuracy
Function Resolution
10pF
0.1nF
1nF
10nF
Input Protection: 600V DC or 600V AC RMS
±(3% ± 5 digits)
100.0uF 0.1uF ±(4% ± 5 digits)

5.000Hz
50.00Hz
500.0Hz
5.000kHz
±(1.2% ± 3 digits)
Frequency
(Auto-ranging)
Range
Accuracy
Function Resolution
0.001Hz
0.01Hz
0.1Hz
1Hz
Sensitivity: >0.5V RMS while ≤1MHz,
Sensitivity: >3V RMS while >1MHz
Input Protection: 250V DC or 250V AC RMS
±(1.5% ± 4 digits)
50.00kHz
500.0kHz
10Hz
100Hz
10.00MHz 1kHz
Range
Test current 1.4mA DC and open circuit voltage 2.8V DC
Built in Buzzer will be sound if the circuit resistance is less
than 50Ω
Function
Diode Test
Overload Protection: max 600V DC or 600V AC RMS
Continuity
6. Operating Instructions
6.1. Measuring Sound Level
• Set the function switch to the “dB” position.
• Move the meter to face the microphone to a sound source in a
horizontal position.
• The C-weighting curve is nearly uniform over the frequency range
from 30 to 10,000Hz, thus giving an indication of overall Sound
level.
• The Fast response is suitable to measure shout bursts and peak
values from sound source.
• The sound level will be displayed.
Note: Strong wind (over 10m/sec.) striking the microphone can cause
misreading for measurement in windy locations, a windscreen
should be used in front of microphone.
6.2. Measuring Humidity
• Humidity Measurement for indoor.
• Set the function switch to the ON position.
• Move the meter and place in the room.
• Read the %RH on the display after about two hours.
9

6.3. Measuring Light
• Set the function switch to the “Lux” scale and set the range to
desired (“Lux” or “x10 Lux”) range.
• Move the meter to face the photo detector to a light source in a
horizontal position.
• Read the illuminance nominal from the LCD display.
• Over-range: If the instrument only display one “1” in the M.S.D. the
input signal is too strong, and a higher range should be selected.
• When the measurement is completed. Remove the photo detector
from the light source.
• Spectral sensitivity characteristic: To the detector, the applied photo
diode with filters makes the spectral sensitivity characteristic almost
meet C.I.E. (International Commission on Illumination) photopia
curve V (λ) as the following chart described.
100% (Relative Sensitivity) Spectral Sensitivity
Wave length (nm)
80%
60%
40%
20%
0
V(λ)
400 500 600 700
10
Recommended Illumination:
Locations Lux
• Office
Conference, Reception room 200 to 750
Clerical work 700 to 1,500
Typing drafting 1000 to 2,000
• Factory
Packing work, Entrance passage 150 to 300
Visual work at production line 300 to 750
Inspection work 750 to 1,500
Electronic parts assembly line 1500 to 3,000
• Hotel
Public room, Cloakroom 100 to 200
Reception, Cashier 200 to 1,000

• Store
Indoors Stairs Corridor 150 to 200
Show window, Packing table 750 to 1,500
Forefront of show window 1500 to 3,000
• Hospital
Sickroom, Warehouse 100 to 200
Medical Examination/Operating room 300 to 750
Emergency Treatment 750 to 1,500
• School
Auditorium, Indoor Gymnasium 100 to 300
Class room 200 to 750
Laboratory Library Drafting room 500 to 1,500
6.4. Measuring Temperature
Temperature Measurement for outdoor:
• Set the function switch to the °C position or °F position.
• Then the display will show the environment temperature reading
value °C or °F respectively.
• Insert the black plug of temperature probe the COM jack and red
plug to the “V / Hz% / Ω / CAP / °C jack”.
• Touch the end of the temperature sensor to the area or surface of
the object to be measured. The display will show the temperature
reading value °C or °F respectively.
6.5. Measuring DC Voltage
• Insert the black test lead banana to the COM jack and red test lead
banana to the “V / Hz% / Ω / CAP / °C“ jack.
• Set the function switch to the DCV ranges to be used and connect
test leads connect test leads across the source or load under
measurement.
• Set the function switch at DCmV ranges to be used connect test
leads across the source or load under measurement.
• Read the LCD display. The polarity of the red connection will be
indicated when making a DC measurement.
• Press the Hz% button to indicate “Hz”.
• Read the frequency on the display.
• Press the Hz% button again to indicate “%”.
• Read the % of duty cycle on the display.
11

6.6. Measuring AC Voltage
• Insert the black test lead banana to the COM jack and red test lead
banana to the “V / Hz% / Ω / CAP / °C“ jack.
• Set the function switch to the AC ranges to be used and connect
test leads across the source or load under measurement.
• Read the LCD display. The polarity of the red connection will be
indicated when making an AC measurement.
• Press the Hz% button to indicate “Hz”.
• Read the frequency on the display.
• Press the Hz% button again to indicate “%”.
• Read the % of duty cycle on the display.
6.7. Measuring DC Current
• Insert the black test lead banana plug into the negative COM jack.
and the red test lead banana plug into the “uA/mA” or “10A” jack.
• For current measurements up to 4000uA DC, set the function
switch to the µA position and insert the red test lead banana plug
into the uA/mA jack.
• For current measurements up to 10A DC, set the function switch to
the yellow 10A position and insert the red test lead banana plug
into the 10A jack.
• Press the MODE button to indicate “DC” on the display.
• Remove power from the circuit under test, then open up the circuit
at the point where you wish to measure current.
• Touch the black test probe tip to the negative side of the circuit.
• Touch the red test probe tip to the positive side of the circuit.
• Apply power to the circuit.
• Read the current in the display.
6.8. Measuring AC Current
• Insert the black test lead banana plug into the negative COM jack.
and the red test lead banana plug into the “uA/mA” or “10A” jack.
• For current measurements up to 4000uA AC, set the function
switch to the uA position and insert the red test lead banana plug
into the uA/mA jack.
• For current measurements up to 400mA AC, set the function switch
to the mA position and insert the red test lead banana plug into the
uA/mA jack.
12

• For current measurements up to 10A AC, set the function switch to
the yellow10A position and insert the red test lead banana plug into
the 10A jack.
• Press the MODE button to indicate “AC” on the display.
• Remove power from the circuit under test, then open up the circuit
at the point where you wish to measure current.
• Touch the black test probe tip to the neutral side of the circuit.
• Touch the red test probe tip to the “hot” side of the circuit.
• Apply power to the circuit.
• Read the current on the display.
• Press the Hz% button again to indicate “%”.
• Read the % duty cycle on the display.
• Hold the Hz% button to return to current measurement.
6.9. Measuring Capacitance
• Set the function switch to the CAP position.
• Insert the black test lead banana plug into the negative COM jack.
• Insert the red test lead banana plug into the “V / Hz% / Ω / Cap /
°C” jack. (If value is not zero in the display. Press the REL button to
zero)
• Touch the test probe tips across the part under test.
• Read the capacitance value on the display.
• The display will indicate the proper decimal point and value.
6.10. Measuring Frequency
• Set the function switch to the HZ position.
• Insert the black test lead banana plug into the negative COM jack.
• Insert the red test lead banana plug into the “V / Hz% / Ω / Cap /
°C” jack. (If value is not zero in the display. Press the REL button to
zero)
• Touch the test probe tips across the part under test.
• Read the frequency value on the display.
• The display will indicate the proper decimal point, symbols (Hz,
kHz, MHz) and value.
6.11. Measuring Resistance
• Set the function switch to the Ω position.
• Insert the black test lead banana plug into the negative COM jack.
13

• Insert the red test lead banana plug into the “V / Hz% / Ω / CAP /
°C” jack.
• Indicate “OL” “MΩ” on the display.
• Touch the test probe tips across the circuit or part under test. It is
best to disconnect one side of the part under test so the rest of the
circuit will not interfere with the resistance reading.
• Read the resistance on the display.
6.12. Measuring Diode
• Set the function switch to the Ω position.
• Insert the black test lead banana plug into the negative COM jack.
• Insert the red test lead banana plug into the “V / Hz% / Ω / CAP /
°C” jack.
• Press the MODE button to indicate “ “ and “V” on the display.
• Touch the test probes to the diode under test. Forward voltage will
typically indicate 0.400 to 0.700V. Reverse voltage will indicate
“OL”. Shorted devices will indicate near 0V and an open device will
indicate “OL” in both polarities.
6.13. Audible Continuity Test
• Set the function switch to the Ω position.
• Insert the black test lead banana plug into the negative COM jack.
• Insert the red test lead banana plug into the “V / Hz% / Ω / CAP /
°C” jack.
• Press the MODE button to indicate“ “ and “Ω” on the display.
• Touch the test probe tips to the circuit or wire you wish to check.
• If the resistance is less than approximately 50Ω, the audible signal
will sound. If the circuit is open, the display will indicate “OL”.
6. 14. Non-Contact AC Voltage Test (NCV)
• Set the function switch to the HZ position.
• Move the meter and the face of the NCV detector to an ACV source.
• If source voltage is between 50-1000V the NCV indicate lamp will
light.
14

7. Maintenance
Battery and Fuse Replacement
If the sign “ ” appears on the LCD display, it indicates that the battery
should be replaced. Remove screws on the back cover and open the
case. Replace the exhausted battery with new batteries.
Fuses rarely need replacement and blow almost always as a result of the
operator’s error. Open the case and replace the blown fuse with ratings
specified.
Warning:
Before attempting to open the case, be sure that test leads have been
disconnected from measurement circuits to avoid electric shock hazard.
Replace fuse only with specified ratings:
Fuse1: F10A / 600V fast blow.
Fuse2: F500mA / 660V fast blow.
15

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South Africa Australia