Sourcetronic MPK-2000e User manual

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MPK-2000e
Digital micro-ohmmeter
User’s guide
GU-1294
© 2008 SOURCETRONIC. All rights reserved.
Printed in Germany.

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
Safety Precautions
• This equipment should be operated only by qualified and duly trained people,
closely observing the corresponding safety regulations and instructions
contained in the present User guide.
• It should be checked that the item to be measured is voltage free.
• Before starting with the measurements, be sure that the battery is well charged
and that the line voltage is between specified limits.
• Do not connect or disconnect the test leads during the measurement.
• There are no adjustable parts or parts that can be replaced by the user within the
equipment. Taking out the Control Panel in order to have an access to the
internal parts may be dangerous as there are high voltages inside, capable of
causing fatal accidents.
• Cleaning of this instrument should be carried out using a soft cleaning liquid,
after verifying that it doesn't attack the plastic parts used in the case and in the
Control Panel of this equipment.
This equipment should be used only by a trained and competent
person, strictly applying suitable safety rules.
Used symbols

Caution, refer to User Guide.

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Index
1. Description...........................................................................................................6
1.1. Operating principle........................................................................................6
2. Control panel........................................................................................................7
3. Power supply .......................................................................................................8
3.1. Battery condition ...........................................................................................8
3.2. Battery charger .............................................................................................8
4. Measurement.....................................................................................................10
5. Messages...........................................................................................................12
6. Some notes about accuracy...............................................................................13
7. RS232 output.....................................................................................................14
8. Cleaning.............................................................................................................14
9. Replacement fuse..............................................................................................14
10. Technical specifications...................................................................................15
11. Warranty ..........................................................................................................17

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1. Description
The MPK-2000e micro-ohmmeter is a portable, microprocessor controlled
instrument, used to accurately measure very low contact resistances of
breakers and switches, busbars, transformers and engines windings, etc,
with test currents from 1 mA to 10 A.
• Kelvin architecture (four-terminal method).
• Digital reading, alphanumeric display.
• Up to 4½ digits readings.
• Powered by rechargeable battery or mains supply.
• 0.1 µΩresolution.
• 200 Ωmaximum reading.
1.1. Operating principle
This device uses the Kelvin Bridge architecture, with four terminals,
avoiding testing leads resistance to cause error during measurement. The
operator may choose test current and the reading is obtained by
comparison through internal high-stability standards. The result appears
in the alphanumeric display that is very easy to read.

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2. Control panel
Fuse.
Power cord connector.
On/Off switch.
Battery charge indicator.
Current terminal (C+).
Potential terminal (P+).
Potential terminal (P-).
Current terminal (C-).
RS232 data output.
Alphanumeric display. Shows both
the measured resistance value and
messages to the operator.
Start key.
Stop key.
Hold key. It retains the last
measurement in the display.
Battery key. To measure the battery
charge condition.
Test current control.
Range and test current selector.
On led.

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3. Power supply
Mains supply or internal battery powered
Battery: rechargeable, 12 V - 7 Ah.
Mains: 100 - 240 V~
3.1. Battery condition
The charge condition of the battery can be verified before or during the
resistance measurement. In order to achieve that, the operator has to
press the battery key while the equipment is turned on. The bargraph
shows remaining charge as a percentile value. If during measurement the
charge of the battery achieves a critical level, the display will show the
BAT message notifying that the charge level is low. After a few minutes
the measurement will be automatically interrupted in order to preserve the
battery from a deep discharge that is prejudicial for its expected useful
life.
3.2. Battery charger
This equipment has an internal battery charger with a smart,
microprocessor-controlled circuit, which adjusts the battery charge to the
optimized parameters to ensure the maximum service life.
Charging procedure:
• Check that the On/Off switch is in Off.
• Connect the equipment to the mains supply.
• The battery charge indicator will keep on lightning with a red light
up to completing the charge. At that point, it will change to a green light,
being like this up to the equipment disconnection from the mains supply.

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If, during the battery charge, the equipment is turned ON, the charge will
be momentarily
interrupted, returning to the charge process once the
equipment is turned OFF.
The rechargeable battery does not show the “memory effect” and there
are no restrictions to start charging it as many times as is needed.
However the battery could be damaged
if remains in deep discharge for a
while.
To avoid this effect, charge the battery before
left the equipment in
storage and don’t let pass more than 30 days without recharge, even if
the instrument wasn’t used (under storage, the battery loses part of it
s
charge).
At the end of battery useful life, the battery must be recycled or
disposed of properly, in order to protect the environment.

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4. Measurement
It should be checked that the item to be measured is voltage free.
1. Before turning the equipment On, connect the test leads to the item to
be measured and to the front panel terminals.
The alligator clamps in the drawings are only for illustration.
2. Using the test current selector , choose the range and the current
to be used.
3. Choose the power supply to use. If you are going to use the battery,
advance to the following point. If you are going to use the mains
supply, plug the power cord into the connector .
4. Switch the equipment On using the On/Off .
5. The PRESS START message will appear showing that measurement
can be started. Press the Start key. Depending on the position of
the test current control the LOW CURRENT message will turn
up.

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6. Turning the test current control clockwise increases the current.
Adjust this control until obtaining the desired value or until the current
indicator (bargraph) indicates 100%. The bargraph will show the test
current value as a percentage of the nominal value selected by using
the test current selector .
7. The lowest current for measuring is 10% of the nominal value. It is
important to consider that the measurement errors increase while test
current decreases. The equipment accuracy is specified for test
currents higher than 80%.
8. The display will show the resistance value measured and the
corresponding unit (Ω[ohms], mΩ[milli-ohms] or µΩ[micro-ohms]).
9. The value can be retained in the display by pressing the hold key.
Pressing this key again, the value will be released.
10. Press the Stop key in order to finish the measurement. Do not turn
Off the equipment without pressing the Stop key before.
11. Finally, when finishing measurements, turn the equipment Off using
the On/Off switch.
Precaution:
Do not connect or disconnect the test leads during the
measurement.

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5. Messages
SOURCETRONIC MPK-2000e
When turning the equipment On using the On/Off switch, this
introductory message appears for a while. During that time, the
equipment carries out some functional checking.
WAIT...
This message appears each time the equipment needs to adjust any
parameter in order to optimize the readings.
PRESS START
The equipment is ready to start a measurement, thus the operator has to
press the Start key.
LOW CURRENT
It shows that the test current is not enough to carry out the reading. It
appears at the beginning of each test and it keeps on being there up to
the operator rotates the test current control clockwise, as necessary
for the test current to be higher than 10 % of the nominal current in the
scale. The inappropriate connection of the cables may cause a difficult
circulation of test current. If this message keeps on being displayed,
please check that the current cables are connected appropriately.
OVERRANGE
It indicates that the measured resistance is higher than the maximum
value readable in the selected range.
H
Indicates that the value is the one retained in the memory when pressing
the hold key.
BAT
It shows that the battery is quite discharged. It is necessary the battery to
be recharged.

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6. Some notes about accuracy
In order to obtain the specified accuracy, the operator has to adjust the
test current to a value higher than the 80% of the nominal value. If it were
necessary, it is possible to use a lower current, but by doing this the
accuracy will be affected.
MPK-2000e has an auto-compensation system that automatically
eliminates the error produced by internal offset. Thus, it is not necessary
to carry out measurements by reversing the polarity in order to compute
the average value. Nevertheless, if the operator suspect that there is a
difference of temperature between the contact points that would can
generate thermoelectric voltages, it is necessary to carry out two
measurements by reversing the current cables and so, the circulation
sense of the current through the resistance under measurement. The
resistance value to be measured will be the average between the values
in one sense and in the contrary (direct and inverse current).

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7. RS232 output
The equipment has an RS232 data output in the control panel that can
be used to register measurements in a serial printer or data collector. The
outputs are the following ones:
Pin 2: Rx ; Pin 3: Tx ; Pin 5: Gnd;
Rate: 4800 bps
8 bits - no parity - 1 stop bit (8,n,1)
Note: In order to assure the compatibility with most printers available in
the market, the resistance units are shown with the following symbols:
uR = micro-ohm
mR = milli-ohm
R = ohm
8. Cleaning
The panel, terminals and connectors of the equipment must stay dry and
clean. Cleaning should be made using a wet cloth in water and a soft
detergent or isopropyl alcohol (be sure that the products to be used for
cleaning does not affect plastic goods).
9.  Replacement fuse
To check the instrument fuse , remove it with a screw driver. If the fuse
is ruptured replace it by another with the following specifications:
Fuse Schurter, model SPT 5x20 (Time-lag) 5A/250V. High breaking capacity.

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10. Technical specifications
Test currents : 1 mA - 10 mA - 100 mA - 1 A - 10 A.
Each current may be continuously adjustable from
0 to 100%.
Resistance ranges : 0 - 2000 µΩ@ 10 A
0 - 20 mΩ@ 10 A
0 - 200 mΩ@ 1 A
0 - 2000 mΩ@ 100 mA
0 - 20 Ω@ 10 mA
0 - 200 Ω@ 1 mA
Resolution : 0.1 µΩ@ 10 A
Output voltage : Up to 10 Vd.c. @ 1 A (open circuit).
Measurement principle : Four-terminal, Kelvin-type.
Basic accuracy : ± (0.10% of reading + 0.005% of full range)
Advanced features : Digital direct reading of very low resistances in the
alphanumerical display, with up to 4½ digits. Very
fast and accurate measurements.
Serial data output : RS232 @ 4800 bps. Suitable for data collection in
an external serial printer, computer or data-logger.
Environmental protection : IP54 with closed lid.
Safety class : Meets the requirements of IEC 61010-1:1990,
IEC 61010-1:1992 amendment 2
Power supply : Rechargeable battery 12 V - 7 Ah or 100-240 V~
mains supply.
Built-in battery charger : 100-240 V~ mains supply.
Operating temperature
range :
-5°C to 50°C
Storage temperature range : -25°C to 65°C
Humidity range :
95% RH (non condensing)

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Weight : Approx. 8,8 kg (including battery and accessories)
Dimensions : 378 x 308 x 175 mm
Accessories : 2 Combined current and potential leads (1.8 m).
1 Communication cable (RS232).
1 Power cord.
1 User guide.
1 Carrying bag.
Subject to technical change without notice.

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11. Warranty
SOURCETRONIC warrants to the original purchaser that each instrument it
manufactures will be free from defects in material and workmanship under normal
use and service. The warranty period is valid for 12 months, except the built-in
rechargeable battery that has 6 months, and begins on the date of shipment. The
manufacturer's warranty does not apply to any product or accessories which, in the
manufacturer’s opinion, have been misused, altered, neglected, or damaged by
accident or abnormal conditions of operation and handling.
To obtain warranty service, send the equipment, with a description of the difficult,
shipping and insurance prepaid, to SOURCETRONIC. The manufacturer assumes
no risk for damage in transit. SOURCETRONIC will, at its option, repair or replace
the defective equipment free of charge or refund your purchase price. However, if
SOURCETRONIC determines that the failure was caused by misuse, alteration,
accident or abnormal condition or handling, you will be charged for the repair and
the repaired equipment will be returned to you transportation prepaid.
This warranty is exclusive and is instead of all other warranties, express or implied,
including but not limited to any implied warranty or merchantability or fitness for a
particular purpose or use. SOURCETRONIC will not be responsible for any special,
indirect, incidental, or consequential damages or loss of data, whether in contract,
or otherwise.
For application or operation assistance or information on SOURCETRONIC
products, contact:
SOURCETRONIC
Georg-Groening-Strasse 47, D-28209 Bremen, Germany
Fax: (+49) 421 – 277 99 98 - email: [e-mail]
Liability limitation
The liability for malfunctioning of the equipment is limited to the application of the
warranty pursuant to the aforementioned provisions. The manufacturer does not
take any responsibility for any eventual damage due to the use or impossibility to
the use of the equipment such as accidents in the field, loss of profit, etc.

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Notes