MKS Ion Systems 775 User manual

Electrostatic
Fieldmeter
Model 775
Instruction Manual

#19-0775-M Ver. 2

#19-0775-M Ver. 2
Contents
1 Description............................................................................ 1
2 Operation............................................................................... 2
Powering the Meter ............................................................................... 2
Battery Check ......................................................................................... 2
Zeroing the Meter .................................................................................. 2
Taking and Holding a Reading ............................................................... 3
Measurement Accuracy ......................................................................... 4
3 Maintenance......................................................................... 5
4 Specifications ...................................................................... 6
5 Warranty and Service ......................................................... 7

#19-0775-M 1 Ver. 2
Description
Ion Systems Model 775 Electrostatic Fieldmeter is a compact electro-
static fieldmeter used to accurately locate and measure static charge
potentials.
The 775 Fieldmeter features both Sample and Hold measurement
modes that allow measurements to be made in places that would be
difficult to reach or see with other instruments. A set of ranging
lights ensure accurate and repeatable measurement. No range
switching is required as the digital display covers the range of 0 to
±19.99 kilovolts. An analog output jack provides a 1 volt output
corresponding to a 10 kilovolt reading on the meter display. The
circuitry has been designed to make accurate measurements in areas
using air ionization.
The 775 Electrostatic Fieldmeter features
• Pocket-size convenience
• Sample and Hold measurement modes
• Distance ranging lights
• Conductive case and ground snap
• Digital display
• 9 Volt battery power
• Analog output
• A special designed for use in ionized areas
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#19-0775-M 2 Ver. 2
Operation
Powering the Meter
The Model 775 has a slide switch for ON/OFF and a push button
switch for modes. The ZERO knob can be turned to the left or right
to change the zero setting of the display.
Push the slide switch actuator into its upper (ON) position. The
display will come on. To turn the meter OFF, slide the switch down
to its lower OFF position. The display should now be off.
Battery Check
After turning on power to the meter, check the display and make
sure that the low battery indicator “BAT” is not showing on the
display. If the “BAT” indicator is lit, replace the battery as described
in Chapter 3: Maintenance before using the meter.
Zeroing the Meter
Turn on the meter with the on/off switch. Put the meter in the
SAMPLE mode (up position). Place the meter 1 inch (2.54 cm) from
a grounded metal surface. If necessary, adjust the ZERO control
until the display reads zero.
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#19-0775-M 3 Ver. 2
Taking and Holding a Reading
Place the meter 1 inch (2.54 cm) from the object to be measured.
This distance is measured from the stainless steel front panel to the
surface of the object. The meter now displays a reading of the elec-
trostatic field in kilovolts per inch.
With the meter in position 1 inch (2.54 cm) from the object being
measured, press the push-button so that it latches in the upper or
HOLD position. This freezes the reading on the display and allow the
meter to be moved to a position where it can be more easily read or
saved for later reference. When the meter is in the HOLD position,
the word HOLD will appear in the display.
Note The Model 775 is built in a conductive case that
provides the ground reference for the measuring
circuit. For accurate measurements and zeroing,
ensure that the person holding the meter
grounded or discharged by touching ground, or
that the meter is grounded using the ground snap
on the rear of the case.
Note In the SAMPLE position the RANGING LIGHTS
are on. The RANGING LIGHTS are provided to
help you place the meter at the correct distance
from an object. The lights are factory- adjusted to
produce a concentric ring bullseye pattern on a
flat, opaque surface 1 inch (2.54 cm) from the
front edge of the meter. This can most easily be
seen by aiming the meter at a sheet of white
paper.

#19-0775-M 4 Ver. 2
Measurement Accuracy
The accuracy of measurement is dependent on a stable ground refer-
ence and the 1 inch (2.54 cm) measuring distance as previously
noted. It is also dependent on the aspect ratio, relating the size of the
object to be measured to the measurement distance. This ratio
should be at least 3 for best accuracy, meaning that the object should
be at least a 3 inches square (7.62 cm square) when measuring at a 1
inch (2.54 cm) distance.
Accurate measurements may be made at other measurement
distances by scaling the meter range and observing the proper aspect
ratio. For example, at a measurement distance of 3 inches (7.62 cm),
multiply the meter reading by 3 to give a range of 0 to 59.97 kilovolts.
For accuracy, the object being measured at this distance should be at
least a 9 inches square (22.86 cm square).
Note In the HOLD position the RANGING LIGHTS are
off. When the push-button is returned to the
SAMPLE position, the RANGING LIGHTS goes on
and the word HOLD disappears from the display.

#19-0775-M 5 Ver. 2
Maintenance
The only maintenance necessary for the Model 775 Fieldmeter is
occasional changing of the 9V battery. Slide off the battery compart-
ment door on the back of the unit. Carefully remove the battery from
the compartment, noting the routing of the battery clip wires, and
detach the battery clip. Replace with a 9V alkaline battery of the same
type. Carefully reinsert the battery in the compartment, routing the
wires so that they do not interfere with the battery compartment
door. Slide the battery compartment door back into position.
The Model 775 Fieldmeter is factory-calibrated to an accuracy of
better than 5%. No attempts should be made to recalibrate the unit
without factory authorization. The accuracy of measurement is
dependent on stable ground reference and measurement at a precise
1 inch (2.54 cm) distance. The Model 775 Fieldmeter has a basic
accuracy of ±5% measured with 1000 volts on the plate.
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#19-0775-M 6 Ver. 2
Specifications
Input: VDC alkaline battery, battery life in excess of 40 hours,
battery included
Display: 3 1/2 digits, 0.4" (1 cm) digit height
Output: Analog output through miniature jack, 1 V corresponds to 10
KV
Reponse: 5 Hz at analog output, digital display updates 3 times per
second
Features: HOLD and low BATTERY indicators, automatic polarity
Controls: On/off slide switch, SAMPLE/HOLD pushbutton, ZERO
control
Range: ±0.00 to 19.99 KV at 1" (2.5 cm); higher voltages may be
measured at distances greater than 1"
Accuracy: ±5%, chopper stabilized (accuracy unaffected by air ioniza-
tion); least significant digit of display indicates tens of volts
Environment Operates at 0-40
Ground Ground through conductive case or snap fastener
Dimensions 4.2"L x 2.4"W x 0.9"D (10.7 x 6.1 x 2.3 cm)
Weight 5 oz. with battery (141.8 g)
Certifications
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#19-0775-M 7 Ver. 2
Warranty and Service
Ion provides a limited warranty for the Model 775 Fieldmeter. New
products manufactured or sold by Ion are guaranteed to be free from
defects in material or workmanship for a period of two (2) years
from date of initial shipment. Ion’s liability under its new product
warranty is limited to servicing (evaluating, repairing, or replacing)
any unit returned to Ion that has not been subjected to misuse,
neglect, lack of routine maintenance, repair, alteration, or accident.
In no event shall Ion be liable for collateral or consequential
damages.
Caution: The 775 Fieldmeter is a precision electronic instrument. It
must not be subjected to extremes of shock and vibration. Damage
to the field sensor may result from dropping the unit from an exces-
sive height onto a hard surface. Such damage is not covered by the
warranty.
The case of the 775 Fieldmeter is sealed. Breaking the seal voids the
warranty.
To obtain service under this warranty, please contact Ion Technical
Support.
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