ESD-PROTECT EFM 822 Manuale utente
Manual EFM 822 - EP0201011
Electrostatic Field Meter 822
2
Manual EFM 822
Contents
General information on electrostatics ....................................................................................................................... 3
Origin of electrostatic charge ................................................................................................................................... 3
Product description........................................................................................................................................................... 3
Specifications .................................................................................................................................................................. 4
Measuring range ............................................................................................................................................................ 4
Caption ............................................................................................................................................................................... 4
Manual .................................................................................................................................................................................... 5
Measuring principle ..................................................................................................................................................... 5
Application Areas .......................................................................................................................................................... 5
Button Features ............................................................................................................................................................. 5
Initiation ........................................................................................................................................................................... 5
Hold ..................................................................................................................................................................................... 5
Measurement ranges ................................................................................................................................................... 5
Changing the measurement distance .................................................................................................................... 6
Spacers ............................................................................................................................................................................... 6
Display ............................................................................................................................................................................... 6
Battery Monitoring ....................................................................................................................................................... 6
Grounding ......................................................................................................................................................................... 7
Maintenance ......................................................................................................................................................................... 7
Battery Replacement ................................................................................................................................................... 7
Zero Point ......................................................................................................................................................................... 7
Guarantee Items ............................................................................................................................................................. 7
Scope Of Delivery ............................................................................................................................................................... 8
Warning Notices ................................................................................................................................................................. 8
Calibration............................................................................................................................................................................. 8
3 General information on electrostatics
General information on electrostatics
Nowadays ESD1 is a problem at many workstations, because modern microelectronics2 is easily
destroyed by the sequels of ESD. Other branches of industry like e.g. telecommunications-, plas-
tics-, and explosive material industry are also heavily affected by ESD.
ESD causes losses of time as well as high financial losses and can endanger the human health.
Charges of over 1 Volts can emerge on people, clothes, materials and equipment. Devices
that are sensitive to electrostatics can be damaged by electrostatic discharges of less than
1 Volts. Charges of 3 Volts and more can cause sparks. In endangered areas that can cause
explosions.
Origin of electrostatic charge
Triboelectricity3 is caused by attrition of different materials. Electrons are transferred from one
material to the other. As electrons are charged negative the material that releases electrons is
charged positive. The material admitting electrons is charged negative. There are different ways
to avoid or to discharge electrostatic charges. But to find an effective and reasonable solution
first of all the emergence, amount and polarity of the charge have to be found. Our devices are
suitable for that purpose and for the supervision of favored charge.
Product description
The unit is housed into an EMV plastic enclosure. The influence electrode is star shaped. In front
of it in a small distance apart a rotating grounded modulation propeller with the same shape as
the electrode is located. The influence electrode is enclosed by a ring electrode system that is
used as mechanical shield for the propeller wheel and the sensor plate. A 2×12 digit alpha-
numeric LC display is located at the front of the device.
The device has an integrated micro computer with the following functions:
•Conversion of the measured field intensity over the adjusted measurement distance to
the charge in Volts
•one button operation
•permanent supervision of the battery voltage with automatic shut-down
•charge plate mode4
1 electrostatic discharge
2 integrated circuits
3 Greek: tribeia = friction
4 with optional CPS kit
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Manual EFM 822
Specifications
Dimensions (L x W x H): Approx. 7 mm x 122mm x 26mm
Weight: Approx. 13 g
Calibration in parallel plate capacitor: 2 mm x 2 mm, distance 2 mm
Calibration accuracy: < 5%
Battery: 9V alkaline or NiMH battery
Operating time: Approx. 1 h with alkaline battery
Measuring range
Distance
Measuring range
Max.
resolution
1cm
… 1 kV
1V
2cm
… 2 kV
2V
5cm
… 5 kV
5V
1 cm
… 1 kV
1 V
2 cm
… 2 kV
2 V
Caption
1
3
2
4
5
6
7
8
1 Cover cap 5
Spacer
Modulator system 6
Zero point trimmer
3 Button «function/on» 7
Alphanumeric LCD display
4 Grounding jack 8
Battery case (on the back)
5 Manual
Manual
Measuring principle
The electrostatic field meter is a parametric amplifier. The electric field influences a current
proportional to the electrostatic field. The current is amplified and measured with a selective
amplifier. No energy is taken from the field over time means.
No radioactive matters are used!
Application Areas
Detection and Control of electrostatic fields resp. charges, measuring of electric charges, electro-
static charges, very high-resistance voltage sources.
Button Features
On
Press «function/on» 1 time shortly
Hold
Press «function/on» 1 time shortly to switch on or off
Distance
Press «function/on» until „change cm“ appears
Press «function/on» 1 time shortly to change to a new distance or to CPS mode,
wait approx. 2s to select the displayed function
Aus
Press «function/on» 2 times in quick succession
Initiation
By pressing the «function/on» button on the front panel the device is switched on. By pressing
the «function/on» button twice in normal operation the device is switched off.
The black cover cap on the modulator system has to be removed before measuring!
If the «function/on» button is not pressed for about 3.5 min, the device switches off to save
power and to prevent discharge of the accumulator.
old
The device has a hold function to freeze the current measuring value. By pressing the
«function/on» one time the value measured at that time remains in the display. The upper line
shows „Hold“ and in the bottom line the result is displayed. By pressing the «function/on» but-
ton again the hold function is switched off and the current result is displayed.
Measurement ranges
After switching the device on the distance selected distance is 2cm. If you want to measure with
that distance5 you just have to place the device 2cm in front of the object to be measured. For
most cases this distance is ideal because charges up to 16kV can be measured (see specifica-
tions). But there are cases in which the measuring distance should be changed. In case of very
high charges or very rough surfaces the distance should be increased. In case of very low charges
the smallest distance (1cm) should be selected.
5 entspricht dem mitgelieferten Abstandhalter
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Manual EFM 822
Changing the measurement distance
Press «function/on» until the lower line shows „change distance“ (approx. 2 sec). In the upper
line the current distance is shown in cm. By pressing «function/on» the distance can be changed
in the following order:
To select the displayed value wait (without pressing «function/on») until the current measure-
ment value is displayed in the bottom line. In the upper line the new distance is displayed. Con-
tinue measuring using the new distance. The distance is measured from the plate behind the
modulator blade. The plate is located 6.4mm in front of the devices front plane.
After switching the device off and on always 2cm distance are selected
The electrostatic field meter measures the direct voltage field strength. Over the selected dis-
tance the field strength is converted to the charge on the object:
displayed value [V] = field strength [V/m] x distance [m]
Example:
With a distance of 1 cm and a displayed value of 1 V the field strength is:
E = 1. V / ,1m = 1 . V/m
Spacers
The shipment includes 2 spacers for the measurement distance 2cm. Those can be screwed in
the front plate.
Display
The display is a double-spaced alphanumeric LCD display with 12 digits in each row (2 x 12). In
the upper line the selected distance is displayed in cm. In the bottom line the measured charge is
displayed in Volt. From 999V on the display changes to kV display. The displayed value is always
triple-digit:
Examples:
If „overflow! “ is displayed, the distance has to be increased.
Battery Monitoring
The device has permanent battery voltage monitoring. By undercutting a battery voltage of 7.6V
the upper line displays: „Low Battery!“. In that case the 9V battery has to be charged or renewed.
By undercutting 7.1V the display shows “auto off” for about 2s and the device powers off to pre-
vent further damage.
Attention: Exclusively use 9V alkaline or NiMH batteries. Rechargeable batteries have to be
charged outside the device in a suited battery charger. Please pay attention to the manufacturer
instructions! Used batteries can be returned to us or have to be disposed professionally.
2cm 5cm 1 cm 2 cm CPS-
Modus 1cm 2cm ...
578V 3,85kV 24, kV 274kV
7 Maintenance
Grounding
The device has to be grounded properly to measure the amount and the polarity of an electro-
static field. For that purpose the device has to be connected to ground by using the grounding
jack (4). Grounding the device by a grounded person (e.g. over conductive shoes or wrist strap)
touching the grounding jack suffices under most circumstances.
Maintenance
The modulator system or parts of it must not be touched. Those parts have to be protected of
dust, isolating impurity layers, color- or paint haze and condensate. If required the modulator
system can be cleaned with ethyl alcohol and a lint-free cotton cloth.
Battery Replacement
When „Low Battery“ appears in the display the 9V battery has to be charged (accumulator) or
renewed (alkaline). For this the device has to be turned and the battery case has to be opened by
sliding down. The battery has to be taken out and the battery clip pulled off. The clip needs to be
plugged to the new battery and put back with the battery into the device. Finally the battery
case should be closed again.
Zero Point
Under normal circumstances a zero point adjustment is not necessary. If the device does not
show U= V while the modulator system is screened (e.g. mounted cover cap) the zero point
can be adjusted using the trimmer (6) on the right side of the device. The last digit of the display
may be ignored as that error is smaller than the admissible tolerance.
Guarantee Items
We provide a 24 month guarantee in case of proper application according to the manual. Ex-
cluded of the guarantee are: The battery resp. the accumulator, damage by electric shock, wrong
grounding and mechanical damage of the device. The guarantee expires if the device was
opened.
Batteries and accumulators are not allowed in the household waste!
Every consumer must by law, dispose of all batteries and accumulators at a municipal or
commercial collection center, free of charge. Thereby, the disposal will be
environmentally friendly.
Batteries and accumulators are marked with the following symbol:
Electrical and electronic equipment are not allowed in the household waste!
When the equipment is not used anymore, every consumer must by law, separate the
equipment from the household waste and bring it to a municipal collection center. Old
electrical equipment is accepted there free of charge. This will ensure that the old
equipment is handled by experts and it will avoid negative impact on the environment.
This crossed out garbage bin means that you may not dispose of batteries and
accumulators in the household waste. Under this sign you may also find
sometimes, in addition, the following abbreviations related to the materials
contents:
Pb = lead, Cd = cadmium and Hg = mercury.
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Manual EFM 822
Electrical equipment is marked with the following symbol:
Scope of Delivery
The basic equipment of the electrostatic field meter includes the following components:
•Soft bag
•Electrostatic meter
•9V alkaline battery
•Grounding cable with alligator clip
•Manual
•Certificate of calibration
Also available as EFM 822 ZBS including:
•ESD transport case with conductive foam interior
•Electrostatic field meter
•2× 9V NiMH accumulators
•Plug-in charger EC1 9
•Grounding spiral cable with alligator clip
•Manual
•Certificate of calibration
Warning Notices
•The electrostatic field meter must not be opened. By opening the guarantee expires.
•The electrostatic field meter must not be used in explosive areas. No admission for ex-
plosive areas!
•If high charges are possible the electrostatic field meter must be grounded. An adequate
distance must be kept.
•Flashovers on the modulator system must be avoided!
•The use of the device in power plants or comparable areas is prohibited!
•The device can not measure alternating fields > 1Hz!
Calibration
A check of the measurement values is recommended annually.
The black bar under the crossed out garbage bin indicates that
the equipment was put into circulation after August 13, 2 5.
Questo manuale è adatto per i seguenti modelli
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