multicomp pro MP720780 User manual

Handheld Oscilloscope Quick Guide
MP720780, MP720781
MP720782 and MP720783

Multicomp-Pro
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INDEX
1. PRODUCT CERTIFICATION·······················································1
2. SAFETY INFORMATION····························································2
3. HOW TO IMPLEMENT THE GENERAL INSPECTION·····················5
4. HOW TO USE THE OSCILLOSCOPE ··········································6
The Structure of the Oscilloscope··············································································6
Front Panel and Keys······························································································6
Side Panel·············································································································8
Introduction to the User Interface of the Oscilloscope ···················································9
Functional Check·································································································· 10
Probe Compensation····························································································· 11
Probe Attenuation Coefficient Setting ······································································· 12
Safe Use of Probe································································································· 13
5. HOW TO USE THE MULTIMETER············································· 14
About This Chapter······························································································· 14
Instrument Interface ······························································································ 14
6. HOW TO USE THE WAVEFORM GENERATOR（OPTIONAL）······ 16
Connect the output·································································································16
Set the waveform···································································································· 16
7. TROUBLESHOOTING····························································· 17
8. APPENDIX············································································ 19
AppendixA: List of Accessories··············································································· 19
Appendix B: Maintenance and Cleaning ··································································· 19

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1. Product Certification
This product complies with the European Community regulations on
electromagnetic compatibility 2004/108/EC and low voltage 2006/95/EC
Product inspection:
Standards adopted
EN61010-1: 2001 (2nd edition)
Safety requirements for electrical equipment for measurement, control, and
laboratory use
EN61326-1: 2006
Electrical equipment for measurement, control and laboratory use –EMC
requirements
EN61000-3-2: 2000+A2: 2005
Limits for harmonic current emissions (equipment input current≤16 A per
phase)
EN61000-3-3: 1995+A1: 2001
Limitation of voltage fluctuations and flicker in low-voltage supply systems for
equipment with rated current≤16A
Inspection is made under normal settings
The symbol indicating conformity is CE, that is, "Conformite Europeenne"

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2. Safety Information
(Before using this product, please read the safety information in advance)
Safety Terms
Terms in this manual (The following terms may appear in this manual):
Warning: Warning indicates conditions or practices that could result
in injury or loss of life.
Caution: Caution indicates the conditions or practices that could
result in damage to this product or other property.
Terms on the product. The following terms may appear on this product:
Danger: Indicates an immediate hazard or injury possibility.
Warning: Indicates a possible hazard or injury.
Caution: Indicates potential damage to the instrument or other property.
Safety Symbols
Symbols on the product. The following symbol may appear on the
product:
Hazardous Voltage
Refer to Manual
Protective Earth Terminal
Chassis Ground
Test Ground
Safety Requirements
Please read the following safety precautions to avoid personal injury and
prevent damage to this product or any other products connected to it. In order
to avoid possible hazards, this product can only be used within the specified
range.

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Warning:
To prevent electric shock or fire, use a suitable power adapter. Only power
adapters that are dedicated to this product and approved for use in the country
of use may be used.
Warning:
The two channels of the oscilloscope are non-isolated channels. Note that the
channel should use a common reference when measuring, and the ground
wires of the two probes cannot be connected to two non-isolated places with
different DC electrical levels, otherwise it may cause a short circuit due to the
ground wire connection of the oscilloscope probe.
Warning:
Note that the channel should use a common reference when measuring,
otherwise it may cause a short circuit due to the ground wire connection of the
oscilloscope probe.
Schematic diagram of the internal ground wire connection of the oscilloscope:
Ground Clip
Signal Input
Electrical Outlet
Probe AC Adapter
Oscilloscope
Schematic diagram of internal ground connection when oscilloscope is
connected with computer through the port:
Ground Clip
Signal Input
Oscilloscope PC Electrical OutletProbe
USB Cable
When the oscilloscope is AC powered by adapter or connected with AC
powered computer through the port, it is not allowed to measure the primary
power supply of power grid.

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Warning:
If the input port of the oscilloscope is connected to a voltage with a peak value
higher than 42V (30vrms) or a circuit with a peak value of more than 4800 VA,
the following measures shall be taken to avoid electric shock or fire:
Only voltage probes, test wires and adapters with proper insulation
attached to the oscilloscope or accessories suitable for oscilloscope
instrument series products specified by our company shall be used.
Before use, check the multimeter test probe, oscilloscope probe and
accessories for mechanical damage. If damage available, replace it.
Remove all unused multimeter test probes, oscilloscope probes and
accessories (power adapter, USB, etc.).
Firstly, plug the power adapter into the AC socket, and then connect it to
the oscilloscope.
When testing in a CAT II environment, do not connect a voltage higher
than 400 V to any input port.
When testing in a CAT II environment, do not connect a voltage with a
voltage difference of more than 400 V to the isolated input port.
Do not use an input voltage higher than the rated value of the instrument.
Pay special attention when using 1:1 test wires, because the probe voltage
will be directly transmitted to the oscilloscope.
Do not touch the bare metal BNC or banana plug.
Do not insert metal objects into the connector.
Use the oscilloscope only in the specified way.
The voltage rating mentioned in the "warning" information is the limited
value of "working voltage". They represent V ac rms (50-60 Hz) in AC sine
wave applications; and V dc in DC applications. CAT is the prefix, and II
refers to the level. Level II is the low voltage and high energy level, which
refers to the local electrical level applicable to electrical appliances and
portable equipment.

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Only a qualified person should perform internal maintenance.
Check all Terminal Ratings. To avoid fire or shock hazard, check all
ratings and markings on this product. Refer to the user manual for more
information about ratings before connecting to the instrument.
Do not operate without covers. Do not operate the instrument with
covers or panels removed.
Avoid exposed circuit. Be careful when working on exposed circuitry to
avoid risk of electric shock or other injury.
Do not operate if any damage. If you suspect damage to the instrument,
have it inspected by qualified service personnel before further use.
Do not operate in damp conditions.
Do not operate in an explosive atmosphere.
Keep product surfaces clean and dry.
Using the equipment not in accordance with the method specified
by the manufacturer may damage the protection provided by the
equipment.
3. How to Implement the General Inspection
After you get a new oscilloscope, it is recommended that you should
make a check on the instrument according to the following steps:
1. Check whether there is any damage caused by transportation.
If it is found that the packaging carton or the foamed plastic protection
cushion has suffered serious damage, do not throw it away first till the
complete device and its accessories succeed in the electrical and
mechanical property tests.
2. Check the Accessories
The supplied accessories have been already described in the "Appendix A:
List of Accessories" of this Manual. You can check whether there is any loss
of accessories with reference to this description. If it is found that there is
any accessory lost or damaged, please get in touch with our distributor
responsible for this service or our local offices.
3. Check the Complete Instrument
If it is found that there is damage to the appearance of the instrument, or the
instrument can not work normally, or fails in the performance test, please get in
touch with our distributor responsible for this business or our local offices. If
there is damage to the instrument caused by the transportation, please keep
the package. With the transportation department or our distributor responsible

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for this business informed about it, arepairing or replacement of the instrument
will be arranged by us.
4. How to Use the Oscilloscope
The Structure of the Oscilloscope
Front Panel and Keys
The front panel and keys of the oscilloscope are shown in Figure 4:
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10
16
15
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517
3
8
1
2
Figure 4: Front Panel of the Oscilloscope
Description:
1. CH1 and CH2 input connectors.
2. Waveform generator output connector (optional).

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3. Display area.
4. The F1 - F4 keys are multi-function keys. In each menu mode, press the
corresponding key to select the corresponding menu item.
5. After pressing the HOR key, through the key , you can change the
horizontal time base setting, and observe the change of the state
information caused by it; it can also be found that the horizontal time
base display corresponding to thestatus bar has changed correspondingly;
the horizontal displacement of the signal in the waveform window can be
adjusted by pressing .
6. Return key. Press this key to return to the previous menu; when the menu
is the first level, press the return key to close the menu.
7. Measurement menu key (oscilloscope) or range key (multimeter).
8. Zoom or move key:
Function of direction keys : used for the up and down movements of
waveform, the time base changing, the voltage cursor movements and the
trigger of electrical level change in the oscilloscope;
Function of direction keys : used for the left and right movements of
waveform, the voltage position changing and the movements of time
cursor in the oscilloscope.
9. Automatic setting key (oscilloscope) or automatic range key (multimeter).
10. Stop / run key (oscilloscope) or value hold key (multimeter) or turn on/off
the signal output (waveform generator - optional).
11. Input end of the multimeter.
12. Trigger menu key (oscilloscope) or relative value key (multimeter).
13. : Power switch key.
14. Enter the save settings key.
15. Enter the system settings key.
16. Switch key for working state of oscilloscope and multimeter.
17. CH1 / CH2 - channel switch key.

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Side Panel
1
2
3
Description:
1. Probe compensation: 3.3V/1kHz square wave signal output
2. Charging or USB communication interface
3. Bracket

9
Introduction to the User Interface of the Oscilloscope
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1213
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Figure 5: Oscilloscope Interface
Description:
1. The trigger status indicates the following information:
Auto: Automatic mode. The waveform is being collected without triggering.
Trig:A trigger has been detected and post trigger information is being
collected.
Ready: All pre trigger data have been obtained and the oscilloscope is
ready.
Scan: Scan mode. Continuously collect and display waveform data.
Stop: Stop collecting waveform data.
2. Run/stop.
3. Time base display.
4. The pointer indicates the trigger horizontal position.
5. The pointer indicates the trigger position within the current storage depth.
6. Indicating the value of the current trigger horizontal displacement, and
displaying the position of the current waveform window in the memory.
7. Battery power and external power supply indication.
8. Channel 1 waveform.
9. The pointer indicates the trigger electrical level position of the channel.

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10. Channel 2 waveform.
11. The icon indicates trigger-related information, including trigger channel,
coupling mode, trigger type and trigger electrical level. For details, please refer
to P19 Trigger System.
12. The current sampling rate.
13. The channel information reading indicates the voltage position of the
corresponding channel.
The icon indicates the coupling mode of the channel:
"—" means DC coupling
"～" means AC coupling
" " Means ground coupling
14. The pointer indicates the grounding reference point (zero position) of the
waveform displayed in CH2 channel. If there is no pointer indicating the
channel, it means that the channel is not open.
15. The pointer indicates the grounding reference point (zero position) of the
waveform displayed in CH1 channel. If there is no pointer indicating the
channel, it means that the channel is not open.
16. Waveform display area.
Functional Check
Making a quick functional check to verify that the instrument is working
properly. Please proceed as follows:
1. Press the switch at the bottom left of the main unit .
The internal relay will make a slight click. The instrument executes all
self-check items, and the startup screen appears. Press the front panel key
System, the default probe menu attenuation coefficient setting value is 10X.
2. The switch on the oscilloscope probe is set to 10X and connected with
the CH1 channel.
Align the slot on the probe with theplug on the bayonet nut connector (BNC) of

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the CH1 connector and insert it, then turn the probe to the right and tighten it.
Connect the probe tip and ground clamp to the connector of the probe
compensator. Please pay attention to the terminal polarity. The square terminal
represents the signal output, and the round terminal represents the reference
ground.
3. Press the "Auto" key on the front panel.
Within a few seconds, a square wave display (1kHz/3.3Vpp) can be seen, as
shown in Figure 0-1.
Figure 0-1: Automatic Setting
Repeat steps 2 and 3 on the CH2 channel.
Probe Compensation
When connecting the probe to any input channel for the first time, make this
adjustment to match the probe with the input channel. The probe without
compensation or deviation compensation will lead to measurement error. To
adjust the probe compensation, please follow the following steps:
1. Set the probe menu attenuation coefficient to 10X, and set the switch on the
probe to 10X (see "ProbeAttenuation Coefficient Setting" in P9), and connect
with CH1. If a hook probe is used, make sure it is in close contact with the
probe. Connect the probe tip to the signal output connector of the probe
compensator, and connect the reference wire clamp to the ground wire
connector of the probe compensator, and then press the Auto key on the front
panel.

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2. Check the displayed waveform and adjust the probe until the compensation
is correct. See Figure 0-2 and Figure 0-3.
Overcompensation Correct compensation
Under-compensation
Figure 0-2: Display Waveform of Probe Compensation
3. Repeat the steps if necessary.
Figure 0-3: Probe Adjustment
Probe Attenuation Coefficient Setting
The probe has a variety of attenuation coefficients, which will affect the vertical
position factor of the oscilloscope.
To change (check) the set value of probe attenuation coefficient in the
oscilloscope menu, please follow the steps below:
(1) Press the CH1/CH2 key to switch the channel to be used.
(2) Press the F3 to select the desired attenuation coefficient. This setting is
valid until it is changed again.

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Note: The preset setting of the probe attenuation coefficient in the
menu when the oscilloscope is delivered is 10X. Make sure
that the attenuation switch setting value on the probe is the
same as the probe attenuation coefficient option in the
oscilloscope menu.
The setting value of the probe switch is 1X and 10X. See Figure 04.
Figure 0-4: Probe Attenuation Switch
Note: When the attenuation switch is set to 1X, the probe limits the
bandwidth of the oscilloscope to 5 MHz.To use the full
bandwidth of the oscilloscope, be sure to set the switch to
10X.
Safe Use of Probe
The safety ring surrounding the probe body provides a barrier to protect the
fingers from electric shocks. See Figure 05.
Figure 0-5: Finger Safety Ring of the Probe

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Warning: To prevent electric shock when using the probe, please keep
your fingers behind the safety ring on the probe body.
To prevent electric shock when using the probe, do not touch the
metal part of the probe head when the probe is connected to a
voltage source.
Before making any measurements, connect the probe to the
instrument and connect the ground terminal to the ground.
5. How to Use the Multimeter
About This Chapter
This chapter introduces the multimeter function of the oscilloscope step by
step, and provides some basic examples of basic operations and how to use
the menu.
Instrument Interface
The multimeter uses four 4-mm safety banana plug input ends: A, mA, COM,
and .
Multimeter interface:
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8
911 10
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Multimeter Interface

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Description:
1. Measurement type indication:
DCV ------ DC voltage measurement
～ACV ------ AC voltage measurement
DCA ------ DC current measurement
～ACA ------ AC current measurement
Resist ------ Resistance measurement
Diode ------ Diode measurement
Cont ------ On/Off measurement
Cap ------ Capacitance measurement
2.Range indication: Manual means manual range; Auto means automatic
range.
3. Current measurement range.
4. Indicating that there is a USB cable inserted.
5. Battery power indication.
6. “Hold”can keep the current reading on the display.
7. Measurement value and unit.
8. Display of switching resistance, buzzer, diode and capacitance
measurement function.
9. The selected range V or mV in voltage measurement; the selected current
range A or mA in current measurement.
10. To choose AC or DC voltage measurement.
11. To choose to AC or DC current measurement.
12. Display of relative value measurement function (only available when
measuring DC current, DC voltage and resistance).

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6. How to Use the Waveform Generator
(MP720781 & MP720783 only)
The instrument can provide 4 basic waveforms, sine wave, square wave,
ramp wave, pulse wave, and 8 arbitrary waveforms.
Connect the output
Press the Mode button to switch the instrument interface to the waveform
generator function interface. Please note if the upper left corner of the screen
is ON/OFF. If it is OFF, press the run / stop button to switch.
Connect the BNC cable to the port marked GEN Out in the top of the
oscilloscope.
Generator Output Ports
To observe the output of the waveform generator, connect the other end of
the BNC cable to the signal input connector of the oscilloscope.
Set the waveform
(1) Press the Mode button to switch the instrument interface to the waveform
generator function interface.
(2) Select the desired waveform from the menu items below, and the screen
will display the corresponding waveform setting menu.
(3) Set the parameters of the desired waveform through the operation panel
F1-F4 or the up, down, left, and right panel keys.

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7. Troubleshooting
1. The oscilloscope cannot be turned on.
It may be that the battery is completely exhausted. At this time, even if the
oscilloscope is powered by the power adapter, the oscilloscope cannot be
turned on. You need to charge the battery first, and do not turn on the
oscilloscope. Wait for about 15 minutes, and then try to turn on the
oscilloscope. If the oscilloscope still cannot be turned on, please contact us to
serve you.
2. The oscilloscope turns off after a few seconds of startup.
It may be that the battery is exhausted. Check the battery symbol at the top
left of the screen. symbol indicates that the battery is exhausted and must
be charged.
3. After switching to the multimeter, the measurement type is displayed
as E.
It may be that the measurement type was not selected. At this time, press F4,
the measurement type should display the corresponding measurement type.
If E is still displayed, restart the oscilloscope.
4. In the oscilloscope state, the measured voltage amplitude value is 10
times larger or smaller than the actual value.
Check whether the channel attenuation coefficient is consistent with the
actual probe error ratio.
5. In the oscilloscope state, there is a waveform display, but it cannot be
stabilized.
Check whether the source item in the trigger mode menu is consistent
with the signal channel actually used.
Check whether the trigger electrical level has exceeded the waveform
range. Only by setting the parameters reasonably, the waveform can be
displayed stably.
6. In the oscilloscope state, nothing is displayed after pressing

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RUN/STOP.
Check whether the trigger mode of the trigger mode menu is normal or single,
and the trigger electrical level is out of the waveform range. If so, center the
trigger electrical level or set the trigger mode to automatic. In addition, you
can press Auto to automatically complete the above settings.
7. In the oscilloscope state, the display speed becomes slower when the
average value sampling is set in the acquisition mode or the duration is
set longer in the display settings.
It is normal.