omu system NMM830 mini User manual

NMM830 mini
Instruction Manual
DIGITAL MULTIMETER
1. General
The instrument is a pocket digital multimeter, which isused to measure DCV, ACV, and DCA, resistance, diode
and continuity test. It is an ideal tool for labs, household and wireless enthusiasts.
2. Safety notes
1. Do not input a limit value over the range whenmeasuring.
2.When measuring voltage higher than 36V DCV, 25V ACV, check the connection and insulation of thetest
leads to avoid electric shock.
3.Keep the test leads away from the testing pointwhen converting function and range.
4.Don't add voltage to the input terminal whenmeasuring resistance.
3. Specification
1. General specifications
1-1. Displaying: 22mm digit height LCD display.
1-2. Max. Indication: 1999 (31/2) auto polarity indication.
1-3. Sampling rate: approx. 3 times/ sec
1-4. Over Range Indication: MSD displays "1"
1-5. Low Battery Indication: " "
1-6. Operation Environment: (0～40)℃, relativehumidity ＜80%
1-7. Power: 9V battery (NEDA1604/6F22 orequivalent)
1-8. Measurement: 145×85×30mm(Length×Width×Height)
1-9. Weight: Approx. 170g (including a 9V battery)
1-10. Accessories: Operation Manual, Product Certificate, Packing box, Test leads and a 9V battery.
2. Technical specification
Accuracy: ± (a%×reading+d)
Surrounding: (23±5)℃, relative humidity <75%
2.1 DCV
Range
Accuracy
Resolution
200mV
± (0.5%+4)
100uV
2V
1mV
20V
10mV
200V
100mV
600V
± (1.0%+5)
1V
Input impedance: 1MΩfor all ranges.
2.2ACV
Range
Accuracy
Resolution
200V
± (1.2%+10)
100mV
600V
1V
Input impedance: 1MΩ
FrequencyResponse: (40～200)Hz
2.3 DCA
Range
Accuracy
Resolution
20uA
± (1.5%+3)
0.01uA
200uA
0.1uA
2mA
1uA
20mA
10uA
200mA
100uA
10A
± (2.0%+5)
10mA
Max. Input current: 10A(no more than 6seconds)
Overload Protection: 0.2A/250V; 10A/250V fuse
2.4 Resistance
Range
Accuracy
Resolution
200Ω
± (0.8%+5)
0.1Ω
2kΩ
1Ω
20kΩ
± (0.8%+3)
10Ω
200kΩ
100Ω
20MΩ
± (1.0%+15)
10kΩ
OverloadProtection: 250V DC/AC peak value
Note: At range200Ω, firstshort-circuit the meterpenstomeasure the wire resistance. Then subtract it from
the real measurement.
2.4.2.5 Diode and continuity test
Range
Display
Testing condition
Forward voltage drop of diode
Forward DCA
is aprox. 1mA
Backward voltage is apporx.3V
Buzzer makes a long
soundwhile resistance is
less than (70±20)Ω
Open voltageis approx.3V
OverloadProtection: 250V DC/AC peak value
2.6 DCVoltageMeasurement
1. Apply the black test lead to "COM" terminal and thered testleadto “V/Ω” terminal.
2. Set the knob to a proper DCV range, and connect thetest leads crossly to the electric circuit under test.
LCD displays polarity and voltage under test connected bythe redtestlead.
Nota: Firstly, the knob should be set to the highest range ifusers have no idea about the range of voltage
undertest. Then select the proper range based on display value.

NMM830 mini
Instruction manual
DIGITAL MULTIMETER
3. If MSD displays “1", it means the meter is overrange. Please set the knob to a higher range.
4. Do not attempt to input voltage over 600V. Otherwise,it may damage the circuit of the meter.
5. Avoid touching high voltage circuit when measuringit
2.7 AC Voltage Measurement
1. Apply the black test lead to "COM" terminal and thered testleadto “V/Ω” terminal
2. Set the knob to a proper ACV range, and connect thetest leads crosslyto the electric circuit undertest.
Note:
1. Firstly, the knob should be set to the highest range ifusers have no idea about the range of voltage under
test.Then select the proper range based on display value.
2. If MSD displays “1", it means the meter is over range.Please set the knob to a higher range.
3. Do not attempt to input voltage over 600Vrms.Otherwise,it maydamage the circuit of the meter.
4. Avoid touching high voltage circuit when measuringit.
2.8. DC Current Measurement
1. Apply the black test lead to "COM" terminal and thered test lead to “V/Ω” terminal (max. 200mA), or put
thered test lead to "10A" terminal (max. 10A).
2. Set the knob to a proper DCA range, and connect thetest leads in series to the electric circuit under test.
LCDdisplays polarity and current value under test connectedby the red test lead.
Note:
1. Firstly, the knob should be set to the highest range ifusers have no idea about the range of voltage under
test.Then select the proper range based on display value.
2. If MSD displays “1", it means the meter is over range.Please set the knob to a higher range.
3. The max input current is 200mA or 10A (depends onthe insert position of the red meter pen). Excessive
current will melt the fuse. When measuring, if the meterhasno reading display, please check relevant fuse.
2.9 Resistance Measurement
1. Apply the black test lead to "COM" terminal and thered testleadto “V/Ω” terminal.
2. Set the knob to a proper resistance range, and connectthe leads crosslyto the resistance under test.
Note:
1. The LCD displays "1" when the resistance is over theselected range. The knob should be adjusted to a higher
range. When resistance under test is over 1MΩ, the reading shall be stable in a few seconds, which is a
normal status when measuring high resistance.
2. When the input terminal is in open circuit, it displaysoverload.
3. When measuring in line resistor, be sure that the power is off and all capacitorsare released completely.
4.It is absolutely forbidden to input voltage at the rangeof resistance, though
2.10 Diode Test
1. Apply the black test lead to "COM" terminal and thered lead to "V/Ω" terminal (the polarity of red lead
is “+”)
2. Set the knob to “ ” range, connect test leads to the diode under test. The red test lead connects to
diode positive polarity and the reading is the approx.value of diode forward voltage drop.
2.11 ContinuityTest
Set the knob to “ “, range, apply test leads to the two points of tested circuit. If the inner buzzer
sounds,the resistance is less than (70±20) Ω.
4. Maintenance
This is a precise meter; please don't try to modify thecircuit.
Note:
1.Do not input voltage over DC600V orAC 600Vrms.
2.Do not measure voltage on range Ω.
3.Do not use this meter for measurement if the battery isnot correctly placed or the back case is not pro-
perly screwed.
4.Remove the test leads from the testing points and turnoff the meter before replacing battery or fuse
Battery Replacement
Note: Pay attention to the battery status.
Please replace the battery when LCD displays “ “.
Steps:
1.Unscrew the battery cover.
2.Take out the9V battery and replace it with a new one.
3.Install andscrew the battery cover.
Fuse Replacement (This operation could only beprocessedin power off status.)
1.Unscrew the battery cover.
2.Take out thebattery and open the back cover.
3.Please use fuse of the same specification.