Desco 19494 Troubleshooting guide

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Portable Charged Plate Monitor
Operation and Maintenance Instructions
Description
The Desco 19494 Portable Charged Plate Monitor (CPM) is a handheld meter designed to
check the offset voltage and discharge times of air ionizers per ANSI/ESD SP3.3 and ESD
TR53. The meter’s integrated timer measures decay rates from ±1000V to ±100V to determine
the ionizers’ ability to neutralize both positive and negative electrostatic charges within the
coverage area. The 180-degree rotary head with 2.75ʺx 1.25ʺplate allows the operator to
read the display at various angles. The Portable Charged Plate Monitor is calibrated to NIST
standards and include a certificate.

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Safety Precautions
This device is a precision electrical instrument. For the sake of safety, be sure to follow the
instructions described in this manual. mark are precautions that must be followed to use
the product safely.
This device does not conform to explosion-proof specifications. Do not install it
in locations where flammable gases or solvents are handled, such as painting
booths etc. Doing so may result in fire or explosion.
This device is a precision electrical instrument. Avoid installing it in wet, oily,
hot, and humid locations. In particular, avoid locations of high humidity and
condensation. There is a possibility of fire due to breakdown.
Installation
●Do not use this device in the following locations, as doing so may cause malfunctions.
・Locations subject to high or low
temperature, or high humidity
・Dusty locations
・Locations where the device may be
exposed to organic solvents such as
thinner
・Locations where the device may be
exposed to corrosive gas
・Locations subject to flames or explosions
・Locations subject to frequent vibrations
・Locations subject to sudden changes in
temperature or humidity
・Locations subject to condensation
・Locations where the device may be
exposed to water or oil
Maintenance
Regularly remove any built-up dirt etc. from the charged plate. Built-up dirt can cause insulation
faults.
Make sure to turn the main power of the device OFF before cleaning.
Handling
Make sure to connect the earth wire to an appropriate place. Accurate measurements are not
possible if the earth wire is not connected.
Do not touch or insert foreign materials into the sensor portion of this device.
Do not blow ionized air directly into the opening of this device.
Do not place heavy objects on the LCD display of this device.
Do not disassemble or modify the device.
The device may affect medical devices such as hearing aids or pacemakers.
Do not insert any foreign objects into the device. Doing so may result in a short circuit or current
leakage, and cause fire or electrocution.
The battery discharges a small amount of electricity even when the device is turned off. If you do
not intend to use this device for an extended length of time, remove the battery.
If the device emits any abnormal odors or sounds, smoke, or heat, turn OFF the main power
immediately, and contact your point of purchase. Failure to do so may result in fire or a short
circuit.
Do not remove name plates or labels.
Do not do anything with the device that is not described in this manual.

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Packaging
1 Portable Charged Plate Monitor
1 Soft Case
1 Wrist Lanyard
1 Ground Cord
2 AA Alkaline Batteries
1 Certificate of Calibration
Features and Components

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Important Points About Taking Measurements
Grounding
This product requires a ground connection. Do not use this product without grounding it.
Accurate measurements require a reliable ground connection.
If the meter contacts or is too close to a large, charged body, there is the
danger of an electrical discharge. This may cause a breakdown of the
device.
Preparation
1. Insert the battery.
Remove the battery case cover and insert
two AA batteries. Replace the cover.
NOTE
•If you are using the optional AC
adapter, remove the rubber cap
from the adapter terminal before
attaching the AC adapter.
2. Connect the ground cord to the
ground terminal. Connect the
opposite end to ground.
Connect the ground cord securely to the
terminal, and connect its alligator clip to a
grounded object. Accurate measurements
required a reliable ground connection.

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Operation
Measuring Ion Balance
1. Turn the meter on.
Slide the power switch to the ON position.
The meter will chirp then activate.
2. Zero point adjust the meter.
Bring the plate into contact with a
grounded body, and press the 0ADJ
button.
NOTE
•Zero point adjustment must be reset
every time the meter is powered.
3. Set the desired mode.
Press the SELECT button, and the meter
will scroll through the modes shown in the
table on the right.
To measure balance (offset voltage), use
I.B mode.
4. Point the plate at the
measurement location.
The meter will measure the balance.
NOTE
•If the display panel blinks "+1" or "-
1", the charged voltage has
exceeded the measurable range
(over-range). If this occurs, stop
measuring immediately, as this may
cause damage to the meter.
5. To turn the meter off, slide the power switch to the OFF
position.
Mode LED display
I.B Mode I.B
+DECAY Mode +DECAY
-DECAY Mode -DECAY

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Measuring Neutralization (Discharge) Times
1. Turn the meter on.
Slide the power switch to the ON position.
The meter will chirp then activate.
2. Zero point adjust the meter.
Bring the plate into contact with a grounded
body, and press the 0ADJ button.
NOTE
•Zero point adjustment must be reset
every time the meter is powered.
3. Set the desired decay range.
The meter changes modes each time the
SELECT button is pressed. Select +Decay to
measure positive discharge time. Select
-Decay to measure negative discharge time.
The default setting measures from ±1,000V to
±100V.
The setting may also be changed to:
•±1,000V to ±50V
•±1,000V to ±20V.
While holding the SELECT button, press the
START button three times within one
second.
The display will indicate the selected decay
range for two seconds then return to the
standby mode.
Press the START 3 times for less
than 1 second while holding down
SELECT button.

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4. Point the plate in the airflow of
the ionizer to be measured and
press the START button.
Voltage will apply onto the plate, and the
meter will measure the amount of time
needed to neutralize it.
NOTE
•If the display panel blinks "+1" or "-1",
the charged voltage has exceeded the
measurable range (over-range). If this
occurs, stop measuring immediately,
as this may cause damage to the
meter.
5. The meter will chirp and display
the neutralization time when the
measurement is completed.
The neutralization time in seconds is
displayed at the bottom of the display.
6. To turn the meter off, slide the power switch to the OFF
position.

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Adjustment and Maintenance
Rotating the Sensor Head
The 180-degree rotary head with 2.75ʺx 1.25ʺ
plate allows the operator to read the display at
various angles.
The sensor head rotates in 45-degree increments.
When rotating the head, stop at angles where the
sensor head clicks into place.
Battery Indicator
The remaining battery charge is displayed on the
lower left of the display panel.
Replace the battery when the icon shows only one
bar remaining.
Error Display
Er3 will appear on the display and a continuous
audible alarm will sound should the meter fail to
apply sufficient voltage onto the plate. This may be
caused by dirty or moist insulating spacers. Clean
and dry the insulating spacers to solve the error.
Contact Customer Service should the meter
continue to alarm after cleaning the insulating
spacers.
The Portable Charged Plate Monitor uses an
oscillating chopper to take measurements. Er9 will
appear on the display and a beeping audible alarm
will sound should the sensor stop oscillating.
Restart the meter should this occur.
Contact Customer Service should the meter
continue to alarm after restarting it several times.
Insufficient voltage error:
Faulty sensor error:

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Troubleshooting
If the device does not operate correctly, it may be the result of one of the following.
The display panel is not active when the power is turned on.
Cause 1
The battery has not been installed, or the positive and negative
terminals have been connected the wrong way around.
Remedy 1
Correctly install the battery.
Cause 2
The battery has been completely drained.
Remedy 2
Replace the battery with a new one.
The plate voltage discharges rapidly.
Cause
The insulating spacers are dirty, moist, or have oil on them.
Remedy
Clean and dry the insulating spacers.
The display does not change when approaching the measurement location.
Cause
The sensor is faulty.
Remedy
If an error message is displayed or you cannot hear an oscillating sound
from the sensor, the sensor must be replaced. Contact Customer
Service and ask for an RMA to be issued.
Specifications
Signal detection method
Oscillating chopper method
Display refresh frequency
0.2 seconds
Measurable potential range
0 to ±1999 V (resolution: 1 V)
Measurement time range
0.0 to 99.9 s
Continuous operating limit
Approximately 6 hours (with alkaline battery, I.B mode)
Sensor head rotation angle
180° (stops every 45°)
Display
LCD display
Mode switching
Switch modes by pressing SELECT button
Battery check
Remaining charge displayed in display panel
Battery
Two AA batteries, Power adapter (sold separately)
Operating temperature/ humidity
range
10 to 40° C, 60% RH or less, non-condensing
Measurement accuracy
±10% rdg ±2 digit
Dimensions
2.8 in. x 1.2 in. x 6.9in.
(70 mm x 30 mm x 174 mm)
Plate dimensions
2.8 in. x 1.3 in.
(70 mm x 32 mm)
Static electricity capacity
20 pF ± 2 pF
Weight (including battery)
8 oz (240 g)
Country of Origin
Japan

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Warranty
See the Desco Warranty -
Desco.com/Limited-Warranty.aspx