MRC MO-2001 User manual

Your purchase of this MILLIOHM METER marks a step forward
for you into the field of precision measurement. Although this
METER is a complex and delicate instrument, its durable structure
developed. Please read the following instructions carefully and
always keep this manual within easy reach.
OPERATION MANUAL
MILLIOHM METER
Model : MO-2001
Hagavish st. Israel 58817 Tel: [phone], Fax: [phone] [e-mail]
PLEASE READ THIS MANUAL CAREFULLYBEFORE OPERATION
MRC.9.21

TABLE OF CONTENTS
1.
FEATURES.....
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2. SPECIFICATIONS...
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2-1 General Specifications....
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2-2 Electrical Specifications.............
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3.
FRONT PANEL DESCRIPTION...................
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3-1 AC Power Input Socket...........................................
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3-2 4 Wires Input Terminal
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3-3 Display............................................
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3-4 Zero Adjust Knob...........
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3-5 Power Off/Range Rotary Switch..............................
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3-6 200 m ohm/2000 m ohm, 20 ohm, 200 ohm,
2000 ohm Select Switch
4.
BASIC 4 WIRES MEASURING PRINCIPLE..................................................
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5. PRECAUTION & PREPARATIONS FOR
MEASUREMENT...................................................................
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6. MEASURING PROCEDURES
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1. FEATURES
* 4 terminal devices for accurate measurement of very low
resistance.
* Ideal for measuring the resistance of the motor coil,
transformer, PCB layout.
* Ideal for testing protective conductors, lightning
conductors and welded points.
* Wide measuring range, 0.1 m ohm - 2000 ohm, 5 ranges.
* 18 mm, large size LCD display, easy to read-out.
* LSI circuit provides high accuracy, reliability and durability.
* Built-in over input.
* Durable & portable housing plastic case with the front
protective cover.
2. SPECIFICATIONS
2-1 General Specifications
Display 18 mm (0.7") LCD,
Max. indication 1999.
Range 200 m ohm, 2,000 m ohm, 20 ohm,
200 ohm, 2000 ohm.
Zero Adjustment External adjustment for zero value of the
display.
Adjusting range approx. 100 counts.
Input Terminal 4 terminal input, accurate for low ohms
measuring.
Over input Indication Indication of "1".
Sampling Time Approx. 0.4 sec.
Operating Temp. 0to 50C ( 32to 122F ).
Operating Humidity Less than 80 % R.H..
1

Power Supply AC 110V 15%, 50/60 Hz
or AC 220V/240V 15%, 50/60 Hz.
Power Consumption Less than 2 VA.
Dimension 160 x 120 x 85 mm,
with housing front cover.
Weight Approx. 680 g (1.5 LB).
Standard Power Cable.............................1 PC.
Accessories 4 wire with 2 kelvin clips...........1 pair.
Instruction Manual....................1 PC.
2-2 Electrical Specifications ( 23 5 蚓 )
Range
Resolution
Test current
Accuracy
200 m ohm
0.1 m ohm
100 mA
0.75% + 4d)
2000 m ohm
1 m ohm
10 mA
20 ohm
10 m ohm
10 mA
200 ohm
0.1 ohm
1 mA
0.75% + 2d)
2000 ohm
1 ohm
1 mA
Range
Open circuit voltage
200 m ohm Approx. 3.8 V DC
2000 m ohm Approx. 3.4 V DC
20 ohm Approx. 3.4 V DC
200 ohm Approx. 3.2 V DC
2000 ohm Approx. 3.2 V DC
Remark :
Spec. tested under the environment RF Field Strength less
than 3 V/M & frequency less than the 30 MHz only.
2

3. FRONT PANEL DESCRIPTION
Fig. 1
3-1 AC Power Input Socket
3-2 4 Wires Input Terminal
3-3 Display
3-4 Zero Adjust Knob
3-5 Power Off/Range Rotary Switch
3

4. BASIC 4 WIRES MEASURING PRINCIPLE
The DIGITAL MILLIOHM METER is the precision,
wide range & small resistance with high resolution
measuring instrument. As for preventing any measuring
errors, especial to avoid the influence of "LEAD STRAY
RESISTANCE" or "TEST WIRE'S RESISTANCE". The
meter is designed according the following "4 WIRES
MEASURING PRINCIPAL" to let the meter within high
accuracy.
Fig. 2
* Please refer to 2.2 Electrical Specification ( page 3 ),
each range exist the exciting test current ( from
Hi to Lo terminal ).
* The standard current is dropped to the unknown resistor
Rx.
* From the terminal Rx1, Rx2 can measure a voltage :
Vx = Is x Rx.
* According the Vx value, then meter can get the unknown
resistance (Rx) values from following formula :
Rx = Vx
Is
* The measured resistance between Rx 1 and Rx 2 is not
affected by any stray resistance of test wire.
4

5. PRECAUTION & PREPARATIONS FOR
MEASUREMENT
* Please check carefully if the meter's power supply is
AC 110 V or AC 220 V before operating the meter.
There is a label at the rear of the meter to show the
proper power source outlet AC 110 V or AC 220 V.
* Please don't input voltage to input terminal ( Lo, Rx1,
Rx2, Hi ) to prevent any internal circuit damage.
6. MEASURING PROCEDURES
1) Rotate the " Power off/Range Rotary Switch " ( 3-5, Fig. 1 )
to the convenient & right range 200 m ohm, 2000 m ohm,
20 ohm, 200 ohm, 2000 ohm.
2) After select the above right range, then should make
the following " ZERO ADJ. PROCEDURE " :
a. Short the 2 clips.
b. Rotate the " Zero Adjust Knob " (3-4, Fig. 1) until
the display reading values show the zero values.
Consideration :
* Zero adjustment is necessary for range 200 m
ohm, 2000 m ohm, 20 ohm only.
* Recommend user select 200 m ohm range to
make "ZERO ADJ. PROCEDURE"
3) Connect the 2 clips as following Fig. 3 to measure
the unknown resistance.
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Fig. 3
4)
Connect the 2 Kelvin clips as following Fig. 4 to measure
the unknown resistance between two test points, such
as PCB layout.
Fig. 4
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