multicomp pro MP730424 User manual

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MP730424
Digital Multimeter
User Manual

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Table of Contents
1.Safety Information....................................................................................................1
Safety Terms and Symbols................................................................................................... 1
General Safety Requirements.............................................................................................. 2
Measurement Limits ........................................................................................................... 3
Main Input Terminals (HI Input and LO Input) Measurement Limits ....................................................... 3
Current Input Terminal (I) Measurement Limits ...................................................................................... 4
Sense Terminals (HI Sense and LO Sense) Measurement Limits.............................................................. 4
Measurement Category....................................................................................................... 4
2.Quick Start................................................................................................................5
General Inspection.............................................................................................................. 5
Dimensions......................................................................................................................... 5
Foot Stool Adjustment ........................................................................................................ 6
Front Panel Overview.......................................................................................................... 6
Rear Panel Overview........................................................................................................... 8
User Interface..................................................................................................................... 9
Power On ..........................................................................................................................10
Measurement Connections ................................................................................................11
3.Functions and Operations.......................................................................................13
To Set The Range ...............................................................................................................13
Measurement Speed..........................................................................................................14
Basic Measurement Functions............................................................................................14
Measuring DC Voltage............................................................................................................................ 14
Measuring AC Voltage ............................................................................................................................ 15
Measuring DC Current............................................................................................................................ 16
Measuring AC Current ............................................................................................................................ 17
Measuring Resistance............................................................................................................................. 18
Continuity Test ....................................................................................................................................... 19
Diode Test .............................................................................................................................................. 20
Measuring Capacitance .......................................................................................................................... 21
Measuring Frequency and Period .......................................................................................................... 22
Measuring Temperature ........................................................................................................................ 24
Dual Display.......................................................................................................................25
Data Hold ..........................................................................................................................26

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Math .................................................................................................................................27
Max/Min................................................................................................................................................. 27
dB/dBm .................................................................................................................................................. 27
Relative Value......................................................................................................................................... 28
Data Record Function.........................................................................................................29
Manual Record ....................................................................................................................................... 29
Auto Record............................................................................................................................................ 30
Port Configuration .............................................................................................................31
Serial....................................................................................................................................................... 31
Language ................................................................................................................................................ 31
Backlight ................................................................................................................................................. 31
Clock ....................................................................................................................................................... 31
Default.................................................................................................................................................... 31
4.Measurement Tutorial.............................................................................................33
Loading Errors (DC Voltage)................................................................................................33
True RMS AC Measurements..............................................................................................34
Loading Errors (AC Voltage)................................................................................................35
Crest Factor Errors (non-sinusoidal inputs)..........................................................................36
5.Troubleshooting......................................................................................................37
6.Technical Specifications..........................................................................................38
7.Appendix.................................................................................................................40
Appendix A: Enclosure .......................................................................................................40
Appendix B: General Care and Cleaning ..............................................................................40
Appendix C: Line Fuse Replacement ...................................................................................41

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1. Safety Information
Safety Terms and Symbols
Safety Terms
Terms in this Manual. The following terms may appear in this manual:
Warning: Warning indicates the 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: It indicates an injury or hazard may immediately happen.
Warning: It indicates an injury or hazard may be accessible potentially.
Caution: It indicates a potential damage to the instrument or other property might occur.
Safety Symbols
Symbols on the Product. The following symbol may appear on the product:

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General Safety Requirements
Before any operations, please read the following safety precautions to avoid any
possible bodily injury and prevent this product or any other products connected from
damage. In order to avoid any contingent danger, this product is only used within the
range specified.
Use Proper Power Cord. Use only the power cord supplied with the product and
certified to use in your country.
Product Grounded. This instrument is grounded through the power cord grounding
conductor. To avoid electric shock, the grounding conductor must be grounded. The
product must be grounded properly before any connection with its input or output
terminal.
Limit operation to the specified measurement category, voltage, or amperage
ratings.
Check all Terminal Ratings. To avoid instrument damage and the risk of electric shock,
check all the Measurement Limits and markers of this product. Refer to the user's
manual for the Measurement Limits before connecting to the instrument. Do not
exceed any of the Measurement Limits defined in the following section.
Do not operate without covers. Do not operate the instrument with covers or panels
removed.
Use Proper Fuse. Use only the specified type and rating fuse for this instrument.
Avoid exposed circuit. Do not touch exposed junctions and components when the
instrument is powered.
Do not operate if in any doubt. If you suspect damage occurs to the instrument,
have it inspected by qualified service personnel before further operations.
Use your instrument in a well-ventilated area. Inadequate ventilation may cause
increasing of temperature or damages to the device. Please keep well ventilated and
inspect the intake regularly.
Do not operate in wet conditions. In order to avoid short circuiting to the interior of
the device or electric shock, please do not operate in a humid environment.
Do not operate in an explosive atmosphere.
Keep product surfaces clean and dry.
Only the qualified technicians can implement the maintenance.

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Measurement Limits
The protection circuitry of the multimeter can prevent damage to the instrument and
protect against the danger of electric shock, when the measurement limits are not
exceeded. To ensure safe operation of the instrument, do not exceed the measurement
limits shown on the front panel, it is defined as follows:
The user-replaceable 10A current-protection fuse is on the front panel. To maintain
protection, replace fuse only with fuse of the specified type and rating. About the
specified type and rating of the fuse, please refer to "7 Current Terminal Fuse" in "Front
Panel Overview" on page 6.
Main Input Terminals (HI Input and LO Input) Measurement Limits
The HI and LO input terminals are used for voltage, resistance, continuity, frequency
(period), capacitance, diode, and temperature test measurements. Two Measurement
Limits are defined for these terminals:
HI Input to LO Input Measurement Limit
The Measurement Limit from HI Input to LO Input is 1000 VDC or 750 VAC, which is
also the maximum voltage measurement. This limit can also be expressed as 1000
Vpk maximum.
LO Input to Ground Measurement Limit
The LO input terminal can safely "float" a maximum of 500 Vpk relative to ground,
where ground is defined as the Protective Earth Conductor in the AC mains power
cord connected to the instrument.
As implied by the above limits, the Measurement Limit for the HI input terminal is a
maximum of 1500 Vpk relative to ground when LO Input is at its maximum of 500 Vpk
relative to ground.

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Current Input Terminal (I) Measurement Limits
The Measurement Limit from the current input terminal (I) to the LO Input terminal is 10
A (DC or AC). Note that the current input terminals will always be at approximately the
same voltage as the LO Input terminal, unless a current protection fuse is open.
Sense Terminals (HI Sense and LO Sense) Measurement Limits
The HI and LO sense terminals are used for four-wire resistance measurements.
The Measurement Limit from HI Sense to LO Input is 200 Vpk.
The Measurement Limit from HI Sense to LO Sense is 200 Vpk.
The Measurement Limit from LO Sense to LO Input is 2 Vpk.
Note: The 200 Vpk limit on the sense terminals is the Measurement Limit. Operational
voltages in resistance measurements are much lower –up to ± 3 V in normal operation.
Measurement Category
The safety rating of the multimeter:
1000 V, CAT I
IEC Measurement Category I. The maximum measurable voltage is 1000 Vpk in the HI -LO
terminal.
600 V, CAT II
IEC Measurement Category II. Inputs may be connected to AC mains power (up to 600
VAC) under Category II overvoltage conditions.
Measurement category definition
Measurement CAT I applies to measurements performed on circuits not directly
connected to the AC mains. Examples are measurements on circuits not derived from the
AC mains and specially protected (internal) mains- derived circuits.
Measurement CAT II applies to protect against transients from energy-consuming
equipment supplied from the fixed installation, such as TVs, PCs, portable tools, and
other household circuits.
Measurement CAT III applies to protect against transients in equipment in fixed
equipment installations, such as distribution panels, feeders and short branch circuits,
and lighting systems in large buildings.
Measurement CAT IV applies to measurements performed at the source of the low-
voltage installation. Examples are electricity meters and measurements on primary over
current protection devices and ripple control units.

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2. Quick Start
General Inspection
After you get a new multimeter, 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 the packing boxes or foam cushions are found to have serious damage, keep them
in a safe place until the complete instrument and accessories have passed the
electrical and mechanical tests.
2. Check the Accessories
Check that all parts and accessories as described in the Appendix A: Enclosure of this
Manual are included and in serviceable condition.
3. Check the Complete Instrument
If it is found that there is damage to the appearance of the instrument, or the
instrument cannot work normally, or fails in the performance test, do not use it and
contact the supplier directly.
Dimensions
235 mm
110 mm
295 mm

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Support Feet Adjustment
Unfold the support feet on the bottom of the multimeter.
Front Panel Overview
2
3
45
12
1
6
78
11
910
Figure 2-1 Front panel overview
Item
Name
Description
1
LCD
Display the user interface
2
Menu selection
Keys
Activate the corresponding menu
3
Operation Keys
Save
Collect data in manual record. The instrument saves
current reading each time the Save key is pressed. See page
29, Manual Record.
Record
Access menus of manual record and auto record.
See page 29, Data Record Function.
Run/Stop
Start or stop auto trigger. When the trigger is stopped, the
displayed data will be held.
Math
Perform math operations (Max/Min, dB/dBm) on the
measurement results.
Utility
Set the auxiliary system function, including Language,
Backlight, Clock, Default.
Port
Set Serial port.
4
HI and LO Sense
Terminals
Signal input terminals, used for four-wire resistance
measurements.

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5
HI and LO Input
Terminals
Signal input terminals, used for voltage, resistance,
continuity, frequency (period), capacitance, diode, and
temperature test measurements.
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Range/Direction Keys
When the Range softkey is shown on the right menu, you
can press the key to switch between auto and
manual range. Press to enable manual range, and
increase or decrease the measurement range.
When setting a parameter, press to move the cursor,
press to increase or decrease the value.
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Current Terminal
Fuse
The rating is 10 A, 250 VAC.
To replace the fuse:
Turn off the multimeter and remove the power cord. Use a
flat-blade screw driver to turn the fuse holder
counter-clockwise, and pull out the fuse holder. Put the
new specified fuse into the fuse holder, and insert the
assembly back into the instrument, turning the fuse holder
clockwise to lock it in place.
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AC/DC Current Input
Terminals
Signal input terminals, used for AC/DC current
measurements.
9
Power button
Turn on/off the multimeter.
10
Measurement
Function Keys
DC or AC voltage measurements
DC or AC current measurements
Resistance, continuity, and diode measurements
Capacitance measurements
Frequency/Period measurements
Temperature measurements
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Dual
Press this key to display the function list on the right menu,
select a function, if the function is supported, the reading
will be displayed in the Vice Display.
12
Dual Exit
Press the key to exit dual display mode.

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Rear Panel Overview
1
3
2
54
Figure 2-2 Rear panel overview
Item
Name
Description
1
RS232
Connect the PC through this port.
2
Line Fuse
The fuse rating is 250 V, F1AL. To replace the fuse, see page
41, Appendix C: Line Fuse Replacement.
3
AC Mains Input
AC mains input connector.
4
Chassis Ground
Screw
To ground the chassis.
5
Instrument Cable
Lock
You can lock the instrument to a fixed location using the
security lock (please buy it yourself) to secure the
instrument.

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User Interface
Trigger Mode
Reading
Range Function
Operation Menus
Unit
Status Icon
Figure 2-3 User interface (Single display)
Secondary function
Primary function reading
Primary function
Figure 2-4 User interface (Dual display)
Trigger Mode
Status Icon
Display
Description
Trigger
Auto trigger
Icon
Description
Auto record function is running
Manual record

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Power On
(1) Connect the instrument to the AC supply using the supplied power cord.
Warning:
To avoid electric shock, the instrument must be grounded properly.
(2) Press down the power button at the front panel, the screen shows the boot screen.

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Measurement Connections
After selecting the desired measurement function, please connect the signal (device)
under test to the multimeter according to the method below. To avoid instrument
damage, do not discretionarily switch the measurement function when measuring.
DC Voltage Measurement
DC Voltage
AC Voltage Measurement
AC Voltage
DC Current Measurement
DC Current
AC Current Measurement
AC Current
2-wire Resistance Measurement
I
2-wire Resistance
4-wire Resistance Measurement
I
4-wire Resistance
Continuity Test
Open or Closed Circuit
I
Diode Measurement
Forward Bias
I

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Capacitance Measurement
Capacitance
Frequency/Period Measurement
AC Signal
Temperature Measurement
Temp Transducer
I

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3. Functions and Operations
To Set The Range
The instrument provides auto and manual range. In auto range, the multimeter selects a
proper range automatically according to the input signal; in manual range, you can use
the front panel key or menu softkey to set the range. The auto range can bring a lot of
convenience for users while the manual range provides higher reading precision.
1st Method: Use the front panel key to set the range.
When the Range softkey is shown on the right menu, you can press the key to
switch between auto and manual range. Press to enable manual range, and
increase or decrease the measurement range.
2nd Method: Select the range in the measurement function menu.
Select auto range: In the measurement function menu, press the Range softkey, select
Auto.
Select manual range: In the measurement function menu, press the Range softkey, select
a range except Auto.
Note:
When the input signal exceeds the current range, "overload” will be displayed.
By default, the range is set to Auto at power-on or after a reset.
Auto range is recommended if you are not sure about the measurement range in order
to protect the instrument and obtain accurate data.

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Measurement Speed
The instrument provides three types of measurement speed:
"Low" speed is 4 reading/s; "Mid" speed is 16 reading/s; "High" speed is 65 reading/s.
In DCV, ACV, DCI, ACI and 2-wire / 4-wire resistance measurements, the measurement
speed is selectable.
Basic Measurement Functions
Measuring DC Voltage
This section describes how to configure DC voltage measurements.
Operating Steps:
1. Enable the DCV measurement.
Press on the front panel to enter DCV measurement mode.
2. Connect the test lead.
DC Voltage
3. Set the range.
Press the Range softkey to set the range. Auto range automatically selects the range
for the measurement based on the input.
Note:
1000 V input protection is available in all ranges.
10% over range for all ranges except 1000 V range.
If the reading exceeds 1050 V in 1000 V range, "overload" will be displayed.
4. Set the measurement speed.
Press the Speed softkey to switch between Low, Mid or High. See page 14 ”
Measurement Speed”.

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5. Set the relative value.
Press the Rel softkey to turn on or off the relative operation. For relative operation,
the multimeter subtracts the pre-specified value of REL operation from the actual
measurement result and displays the result. See page 28, Relative Value.
Measuring AC Voltage
This section describes how to configure AC voltage measurements.
Operating Steps:
1. Enable the ACV measurement.
Press on the front panel, press it again to enter ACV measurement mode.
2. Connect the test lead.
AC Voltage
3. Set the range.
Press the Range softkey to set the range. Auto range automatically selects the range
for the measurement based on the input.
Note:
750 V input protection is available in all ranges.
10% over range for all ranges except 750 V range.
If the reading exceeds 787.5 V in 750 V range, "overload" will be displayed.
4. Set the measurement speed.
Press the Speed softkey to switch between Low, Mid or High. See page 14,
“Measurement Speed “.
5. Set the relative value.
Press the Rel softkey to turn on or off the relative operation. For relative operation,
the multimeter subtracts the pre-specified value of REL operation from the actual
measurement result and displays the result. See page 28, Relative Value.

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Measuring DC Current
This section describes how to configure DC current measurements.
Operating Steps:
1. Enable the DCI measurement.
Press on the front panel to enter DCI measurement mode.
2. Connect the test lead.
DC Current
3. Set the range.
Press the Range softkey to set the range. Auto range automatically selects the range
for the measurement based on the input.
Note:
The multimeter uses two kinds of fuses for current protection: the 10 A current
input fuse on the front panel and the built-in 12 A current input fuse.
10% over range for all ranges except 10 A range.
If the reading exceeds 10.5 A in 10 A range, "overload" will be displayed.
4. Set the measurement speed.
Press the Speed softkey to switch between Low, Mid or High. See page 14,
“Measurement Speed “.
5. Set the relative value.
Press the Rel softkey to turn on or off the relative operation. For relative operation,
the multimeter subtracts the pre-specified value of REL operation from the actual
measurement result and displays the result. See page 28, Relative Value.

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Measuring AC Current
This section describes how to configure AC current measurements.
Operating Steps:
1. Enable the ACI measurement.
Press on the front panel, press it again to enter ACI measurement mode.
2. Connect the test lead.
AC Current
3. Set the range.
Press the Range softkey to set the range. Auto range automatically selects the range
for the measurement based on the input.
Note:
The multimeter uses two kinds of fuses for current protection: the 10 A current
input fuse on the front panel and the built-in 12 A current input fuse.
10% over range for all ranges except 10 A range.
If the reading exceeds 10.5 A in 10 A range, "overload" will be displayed.
4. Set the measurement speed.
Press the Speed softkey to switch between Low, Mid or High. See page 14,
Measurement Speed .
5. Set the relative value.
Press the Rel softkey to turn on or off the relative operation. For relative operation,
the multimeter subtracts the pre-specified value of REL operation from the actual
measurement result and displays the result. See page 28, Relative Value.