Kleinwächter EFM-122 User manual

ELEKTROFELDMETER
S YSTEM P ROF . D R . I NG . H ANS K LEINWÄCHTER
ELECTROSTATICFIELD METER
.
EFM-122
Small hand-held Electro-Fieldmeter with digital display and separate sensor to
measure the electrostatic charge.
Display directly the electrostatic voltage potentials (with pre-selected distance)
according the field mill influence principal.

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table of contents
1. General information’s 3
2. Description 3
3. Specifications 4
4. Operation Instruction 4
4.1 Principle of Measurement 4
4.2 Application 4
4.3 Operating 4
4.4 Hold-Function 4
4.5 Ranges 5
4.6 Changing the distance 5
4.7 Display 5
4.8 Error-Messages 5
4.9 Battery Control 5
5. PC-Interface 5
6. Grounding 5
7. Maintenance 6
7.1 Charging the 9V Battery 6
7.2 Zero Adjust 6
7.3 Guarantee 6
8. Warning notice 6
9. Delivery parts 6
10. Operating elements and 7
electrical connections

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1. General information about electrostatic charge
Today electrostatic discharge is a problem on many working places with the use of modern
micro - electronics as e.g. Microchips and there sensibility against it.
There is also a very strong danger for industrial branches as e.g. Telecommunication- ,
Plastics- , and manufactures of explosives.
The loss in manufacturing time as well as high financial damage and the affection of the
health of persons may be cased by ESD (electrostatic discharge).
It is possible that electrical charges of over 10.000 V can build up on human clothes,
materials and equipment. Damage on electronic components may already occur with a
charge of less as 100 V and charges of 3.000 V are able to flash and may be the result of
explosion in hazardous areas.
What is the cause of electrostatic charge?
Trough friction and separation of different materials, called - Tribo Electricity - ( it stays for
the Greek word tribeia which means friction ) will be generated.
The cause is a transfer of electrons between the two materials.
Since the charge of electrons is negative the material depleting electrons has a positive
charge, compare the material enhances electrons shows a negative charge.
There are different ways to prevent or divert electrical charges. However to find a useful and
effective way, first the source and the charge of the electrostatic field has to be located and
the polarity and strength will be measured.
To do so as well as check any chosen steps against electrostatic charge or to control desire
charge our Electro - Field meter is recommended.
Measurement method
The static-field meter has a parametric amplifier. The electrical field causes an alternated
current proportional to the field strength. These current can be measured with a selective
amplifier, without taking away energy of the electrical field.
Through using gold-plated influenz-electrodes no galvanic disturbances are induced.
There is no radioactive material in use !
2. descriptions
The unit is housed into an EMV-plastic enclosure, and the sensor in a metallic cane. The
Influence Measuring Electrode is star shaped. In front to it in a small distance apart a rotating
grounded modulation propeller wheel with the same shape is located. The Influence
Electrode is jacket by a ring electrode system used also as mechanical shield for the
propeller wheel and the sensor - plate. The measurement display is located on top of the
unit. It is a 2x12 digit alphanumeric LC - display. The connection between the sensor and
the handheld unit is a RS 485 serial interface.
The unit consists of built in microprocessors for the following tasks as:
•it considers automatically the measured field strength (V/m) and the pre-selected
distance (cm) to calculate the voltage potential (Volt)
•single push - button control
•permanent Battery – voltage - control with automatic switch off
•control of the RS485 interface

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3. Specifications
Handheld housing dimensions : 70 x 122 x 26mm
Weight : app. 130g
Sensor housing dimensions : d 40mm x 120mm
Weight : ca. 180 gr.
Balance in the plate condenser : 200 x 200mm
Distance : 25mm
Adjustment error : < 5 %
Battery : 9V NiMH battery
Operating time : app. 10 hours
Measure Ranges: Distance 1 cm 0.......8 kV max. Resolution 1 V
Distance 2,5 cm0.....16 kV max. Resolution 2 V
Distance 5 cm0.....40 kV max. Auflösung 10 V
Distance 10 cm0.....80 kV max. Resolution 10 V
Distance 20 cm0...160 kV max. Resolution 20 V
4. operation instruction
4.1 Principle of operation
The Electro-Field meter is working with a parametric amplifier. The charge, caused by
electrostatic induction, is converted to an alternating current proportional to the field strength.
A selective working amplifier measures the current without loss in relation to the field
strength.
There is no use of any radioactive materials in the unit
4.2 Applications
Detection and control of electrostatic fields or charges.
Measuring: electric field strength electric charges, electrostatic charges, extremely high-
resistant voltage sources.
4.3 Operating
Press the „function/on“-key to switch on the unit. Remove the protection cup from the
modulator !
Press the „function/on“-key longer as 2sec. to switch the unit off. The unit will switch off
automatically when the „function/on“-key was not used for about 5 minutes.
4.4 Hold-Function
The unit has a hold-function keeping the measured value stored on the display . Press the
„function/on“-key once shortly to activate the hold function - „hold“ will appear then in the first
row of the display, while the stored value is shown in the second row. To exit the hold-
function, press the „function/on“- key once again shortly and the actual measurement value
will appear on the display.
4.5 Measurement ranges
The last selected distance is indicated when switching – on the instrument.
If this distance is used, the unit has to be positioned in the displayed distance monitoring the
object. The distance should be increased, if the object is high charged or when the object
has a rough surface. The lowest measurement distance of 1cm should be selected, when
low charges are present and the surface of the object has a smooth surface.

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4.6 Change measurement distance
Press and hold the „Distance“-key (with a screw driver through the hole on the right side)
until „change distance“ will appear in the second line. The pre-selected distance in cm will be
displayed in the first line. Press the „function/on“-key shortly to change the distance. With
each short press of the „function/on“-key the proposed distance will appear as follows:
2,5cm => 5cm => 10cm => 20cm =>cps - mode => 1cm ...
When the right distance is shown in the display, please wait (do not press the „function/on“-
key) until the actual measurement value will appear in the second line. The new selected
distance is now also shown in the first line. Please consider this selected distance for the
following measurements. The distance will be measured from the electrode positioned
6.4mm apart from the housing on the modulator side. It is more practical to add 6.4 mm to
any selected distance starting from the front - plate of the unit.
Please note: the distance will be stored !
4.7 Display
The alphanumeric Liquid Crystal Display (LCD) consists of 2 lines for 12 digits each. The
measurement distance in cm will be shown in the first line, while the voltage reading in volts
is displayed in the second line. When the level of 999 volts is reached, the display will switch
automatically into the kV-mode. The display of the voltage reading appears always in 3
digits, such as: 578 V 3,85 kV 24.0 kV and 274 kV. Select a greater distance if „overflow !“
appears on the screen !
4.8 Error message
Appears an error message in the display, the unit switch off after 2 seconds. If the same
error message appears again after restart, please send the unit back for repair.
4.9 Battery voltage control
The EFM 022 has a permanent battery-voltage control. If the battery voltage is less than 7,6
V „Low Battery“ appears in the first line of the LCD and the 9V NiMH block-battery has to be
charged or replaced !
Note: Please use rechargeable - NiMH 9V - batteries only!
5. PC-Interface
The EFM 122 has a serial RS 232 Interface. Connect the EFM with the included serial Cable
to a PC. Put the 3,5” Disc into the PC and start “Install”
Following the instructions on the PC.
6. Grounding
The unit has to be connected to ground for correct measurements of voltage levels and
polarity. Use the grounding socket (4) of the unit for the connection to earth potential. The
unit consists of a conductive housing, thus allow the use without grounding cable if the
operator is on earth potential (e.g. wears conductive shoes, uses a wrist strap or touches
grounded parts).

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7. Maintenance
Do not touch the modulator system to prevent mechanical damages. Avoid any insulating
build up as e.g. dust, paint or varnish dust, condensed water or similar influence.
If it is necessary the modulator system may be cleaned with alcohol and a soft fuzzy-free
cloth.
7.1 Charge the 9V NiMH - battery
The 9V block-battery has to be charged when “Low Battery” appears at the display.
Please use only the original Charger to charge the battery.
7.2 Zero Adjust
A zero adjustment is normally not needed. In case, that the unit does not indicate U=00X
while the modulator system is shielded (e.g. grounded person covers the modulator system
with one hand), use the trimmer (6) for zero adjustment. The last digit can be ignored as the
caused measurement failure is much lower than the specified tolerance.
7.3 Guaranty Performance
By correct operation and in accordance to the instruction manual we allow a 24 month
warranty.
The warranty does not include: The NiMH Battery damages by electrical discharge, incorrect
grounding and mechanical damage of the Field Meter.
If you open the unit, you will lose the Guaranty !
8. Warning notice
√It is not allowed to open the Electro field meter. If you open it, you lost the guaranty.
√The Electro field meter is not approved for measurements in explosion hazard areas.
√In the event of very high electrostatic charges, the Electro field meter must be grounded.
Look for an adequate distance to the test object.
√Avoid spark discharges onto the modulator system.
√The use of the unit in power plants is not permitted.
√The Electro-Field meter is not equipped to detect alternating fields > 1Hz.
9. Parts of delivery
•Transport Case with antistatic Foam Interior
•EFM-122 with sensor
•rechargeable 9V NiMH - Battery
•Battery Charger
•Coiled Grounding Cord and Crocodile Clip

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10. Operating elements and electrical connections
Grounding socket Zero - Key
Power Socket 12V-DC PC - Interface
Alphanumeric
LCD – Display (2x12)
“function/on” Key
I
„H“ Key to change the
distance
(only to use with a screw
driver)
Optional accessories
Tripod for fixation of the measure sensor.
measure head MK11
with BNC - Connector (Photo)
or 4mm Banana Plug
To measure directly Voltage up to
± 2kV (Ri > 10
16
Ω)
Photo – Table Tripod

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