Desco 19493 Troubleshooting guide

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Fax [phone] • Website: Desco.com
TB-3041 Page 1 of 6 © 2009 DESCO INDUSTRIES, INC.
Employee Owned
Made in America
Ionization Test Kit
Operation and Maintenance
Description
The Desco Ionization Test Kit allows the 19492 Digital
Static Field Meter to be used to measure the offset
voltage (balance) and charge decay of ionization
equipment. The Test Kit also includes a Charger used to
place a ±1000V charge on the 19498 Conductive Plate,
making it possible to also measure the discharge times
of air ionization equipment per ANSI/ESD SP3.3 Periodic
Verication of Air Ionizers. The 19493 Ionization Test Kit
includes the 19492 Digital Static Field Meter, providing a
highly portable and cost effective means of verifying the
performance of a wide variety of ionization equipment.
Note: The 19492 Digital Static Field Meter is designed to
operate only with the 19493 Ionization Test Kit. It is not
compatible with other brands.
Although not as accurate, the Desco Ionization Test Kit
has been designed to make measurements that
correspond to those made by using a charged plate
analyzer and ANSI/ESD S3.1. The Ionization Test Kit
provides convenience and portability to test per ANSI/
ESD SP3.3 Periodic Verication of Air Ionizers or
Compliance Verication ESD TR53. We recommend
EMIT’s 50555 / 50561 Charged Plate Analyzer if precise
measurements are required.
The Ionization Test Kit includes a slide-on isolated
Conductive Plate, a ±1000 volt Charger and a durable
thermoplastic carrying case with custom cut-outs for all
of the above components along with the model 19492
Digital Static Field Meter.
Charged insulators in the ESD protected area can
adversely impact quality, productivity, and reliability.
“When any object becomes electrostatically charged,
there is an electrostatic eld associated with that charge.
If an ESDS (ESD sensitive) device is placed in that
electrostatic eld, a voltage may be induced on the
device. If the device is then momentarily grounded, a
transfer of charge from the device occurs as a CDM
(Charged Device Model) event. If the device is removed
from the region of the electrostatic eld and grounded
again, a second CDM event will occur as charge (of
opposite polarity from the rst event) is transferred from
the device.” (ESD Handbook ESD TR20.20 section
2.7.5 Field Induced Discharges)
Compliance verication should include periodic checks
with a static eld meter to determine if high
charging material is present in the ESD protected area.
All packaging and other materials that may be
electrostatic generative to 2,000 volts must be kept a
minimum of 12" from ESD sensitive items at all times. It
is proper to rub an item and measure that it can charge.
“In order to mitigate eld-induced CDM (Charged Device
Model) damage, the ESD program shall include a plan
for the handling of process-required insulators. If the
eld exceeds 2,000 volts/inch, steps shall be taken to
either:
A. Separate the insulator from the ESD-sensitive device
by a distance of 30 cm (12 inches); or
B. Use ionization or other charge mitigating techniques
to neutralize the charge.” (ANSI/ESDS20.20 section
8.3)
Other steps that can be taken are to remove the item
from the ESD protected area, periodically coat with a
topical antistat, or replace with a static control protective
version of the item.
Packaging
1 Digital Static Field Meter
1 Conductive Plate
1 Charger
2 9V Alkaline Batteries
1 Data Output Cord
1 Carrying Case
1 Certicate of Calibration
Figure 1. Desco 19493 Ionization Test Kit
Rev. June 2009
TECHNICAL BULLETIN TB-3041

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Fax [phone] • Website: Desco.com
TB-3041 Page 2 of 6 © 2009 DESCO INDUSTRIES, INC.
Employee Owned
Features and Components
DIGITAL STATIC FIELD METER
D. POWER Button: Press to turn the unit ON and OFF.
E. 4mm Stud: Use this stud to ground the Meter using
a 4mm ground cord (not provided - any standard single
wire wrist strap cord can be used).
F. Battery Cover: Slide the cover down to open the 9V
battery compartment.
CHARGER
Figure 2. Digital Static Field Meter features and
components
A
B
C
D
FRONT VIEW
BACK VIEW
E
F
A. HOLD Button: Press to freeze the reading on the
display. Press again to return to normal measurement
operation.
B. RANGE / ZERO Button: Press to select the
measurement range. Press and hold to zero the Meter.
C. Analog Output Jack: A low-voltage replica of the
measured voltage is provided at this output. The voltage
at this output is 1/1000th (±2 kV range) or 1/10,000 (±20
kV range) of the measured voltage.
FRONT VIEW
BACK VIEW
A
B
C
D
Figure 3. Charger features and components
A. Output Contact: The output contact is connected to
an internal power source. When the touch plate located
underneath the unit is connected to ground, the output
contact will provide a charge of the indicated polarity.
The charger is designed so that an operator can press
the rocker switch and touch the plate simultaneously
with the ngers of the same hand.

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Fax [phone] • Website: Desco.com
TB-3041 Page 3 of 6 © 2009 DESCO INDUSTRIES, INC.
Employee Owned
B. Rocker Switch: Press and hold to select the polarity
that will be provided at the Output Contact.
C. Touch Plate: Make contact with the touch plate while
pressing down the rocker switch to provide voltage to the
Output Contact. The operator must be properly
grounded during use.
D. Battery Compartment: Slide the cover down to open
the 9V battery compartment.
Operation
TAKING OFFSET VOLTAGE (BALANCE)
MEASUREMENTS
The Ionization Test Kit has been designed to match the
compact size and hand held convenience of the Digital
Static Field Meter. Use the following procedure to verify
the offset voltage (balance) of air ionization equipment.
This quick and easy procedure will help determine if
the piece of ionization equipment is working within the
manufacturer’s specications or user requirements. It
is extremely important that ionizers be checked
regularly for offset voltage (balance) and discharge
times. An ionizer operating in an out-of-balance
state can place a charge on sensitive electronic
components or assemblies.
Note: The 19492 Digital Static Field Meter is built in a
conductive case. The instrument senses the difference
in potential between the case (and the person holding
the case / ground connection) and the surface under
test. Ensure that the person using the instrument is
grounded or that the rear panel ground snap connection
is utilized to achieve accurate measurements.
INSTALLING THE ISOLATED PLATE ASSEMBLY
The Digital Static Field Meter’s case has two slots along
its sides. The top slot is closest to the face of the
instrument. Slide down the tabs of the Conductive Plate
plate into the top slot of the Meter’s case as far as they
go (see Figure 4).
BATTERY CHECK
The battery should be replaced when “BAT” is indicated
on the display. Always replace the battery with a 9V
alkaline or equivalent battery in order to remain CE
compliant.
ZERO THE METER
Turn the Meter on by pressing the POWER button.
Press the RANGE / ZERO button to set the Meter to
the 2 kV (3 decimal places) range. Point the top of the
Meter approximately 1 inch away from a grounded metal
surface. Use the red LED range guide. The Meter is
properly positioned when the projected red bullseyes
are centered on top of each other. Press and hold the
RANGE / ZERO button until the Meter displays “.000”.
MAKING A MEASUREMENT
Locate the Test Kit in an ionized environment at the
appropriate distance from the device under test. The
static eld displayed is the actual balance of the ionizer
or voltage offset. The display will indicate “1” or “-1”
when the Meter is over-ranged. Change the range of the
unit if necessary. (see Figure 3).
Note: When testing pulsed ionizer systems, the voltage
displayed is constantly changing. This pulse rate may
be faster than the display update rate of the Field Meter,
therefore the displayed voltage is an average of the
actual voltage. The output of the Field Meter is useful in
this situation for more accurate measurements.
Figure 4. Installing the 19498 Conductive Plate
12"
18"
Figure 5. Auditing ionization equipment with the Digital
Static Field Meter and Conductive Plate (Ref: ANSI/ESD
SP3.3)

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Fax [phone] • Website: Desco.com
TB-3041 Page 4 of 6 © 2009 DESCO INDUSTRIES, INC.
Employee Owned
HOLDING THE LAST READING
Press the HOLD button to freeze the reading from the
object on the display and the analog output signal. This
feature allows the operator to move the Meter where it
may be more easily read or saved for later reference.
made at the location where ESD sensitive items are
to be ionized. Air ionizer heaters and air lters (if so
equipped) should be left in their normal conditions during
test.”
ANALOG OUTPUT
The analog output jack labeled “OUT” on the face of
the Meter accepts a standard 2.5 mm monaural phone
plug and is provided so the output of the Digital Static
Field Meter may be connected to an oscilloscope, strip
chart recorder, external meter or other device. Use the
included cord to achieve a connection between the Field
Meter and alternate measuring instrument. The voltage
at this output is 1/1000th (±2 kV range) or 1/10,000 (±20
kV range) of the measured voltage.
TAKING DISCHARGE TIME MEASUREMENTS
In order to verify that an ionizer is operating properly it is
also important that its ability to neutralize or discharge
static electricity is measured. The following procedure
will measure an ionizer’s discharge time:
OPERATING THE CHARGER
The Charger has a momentary rocker-switch that powers
the unit. Holding the switch forward / backward supplies
power to the output terminals.
POLARITY SELECTION
The top of the rocker switch is labeled “+”, and the
bottom is labeled “-”. To provide a POSITIVE voltage
output, touch the plate located underneath the charger,
and press the switch forward at the same time. To
provide a NEGATIVE voltage output, touch the plate
located underneath the charger, and press the switch
downward at the same time.
Note: For the Charger to work correctly, the operator
and Field Meter must be properly grounded. A ground
path to the touch plate must exist.
IONIZER DISCHARGE TIME MEASUREMENTS
Use the Field Meter with the conductive plate in the
appropriate location for measurements.
POSITIVE DISCHARGE TIME MEASUREMENTS
To provide a POSITIVE voltage output, touch the plate
located underneath the Charger, and press the switch
forward at the same time. Momentarily touch the
Charger’s output terminal to the conductive plate
attached to the Field Meter. The meter reads
approximately +1.10 kV. By using a stop watch or other
timing device, determine the time needed for the
voltages to decrease from +1.10 kV to +0.10 kV. This is
the positive discharge time.
Figure 7. Reading the Digital Static Field Meter while in
the ±2 kV range
Hundreds
Tens
Ones
Figure 6. Reading the Digital Static Field Meter while in
the ±20 kV range
Thousands
Hundreds
Tens
Per ESD TR53-2006 Compliance Verication of ESD
Protective Equipment and Materials Air Ionizer Test
Procedure Initial Test Setup “Measurements should be

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Fax [phone] • Website: Desco.com
TB-3041 Page 5 of 6 © 2009 DESCO INDUSTRIES, INC.
Employee Owned
NEGATIVE DISCHARGE TIME MEASUREMENTS
To provide a NEGATIVE voltage output, touch the plate
located underneath the Charger, and press the switch
downward at the same time. Momentarily touch the
Charger’s output terminal to the conductive plate
attached to the Field Meter. The meter reads
approximately -1.10 kV. By using a stop watch or other
timing device, determine the time needed for the
voltages to decrease from -1.10 kV to -0.10 kV. This is
the negative discharge time.
IMPORTANT: A ground path must be provided between
the touch plate of the Charger and the ground reference
of the Field Meter. This is normally provided by holding
the Charger in one hand and the Field Meter with
Conductive Plate in the other.
The battery in the Charger should be replaced annually
or when it is unable to provide approximately ±1100V.
CLEANING
It is important to keep the insulators on the adapter plate
clean and free of contaminates that may cause surface
leakage. To test the performance of the adapter plate,
charge the plate and note the discharge rate in a nonion-
ized area. The self discharge rate to 10% of original
voltage should not be less than ve minutes.
The area around the aperture of the Digital Static Field
Meter must be kept clean to ensure accurate, drift-free
readings. Never touch the aperture with anything. To
remove dust or other particulate matter, use low-
pressure instrument-grade air. To remove more severe
contamination, spray or ush with the smallest practical
amount of clean technical-grade of isopropyl alcohol.
Then allow the instrument to air dry for several hours.
Specications
DIGITAL STATIC FIELD METER
Measurement Range (switch selectable)
Low Range: 0 to ±1.99 kV / inch
High Range: 0 to ±19.99 kV / inch
Measurement Accuracy
Voltage Monitor Output: > ±5% of reading ±10 mV
Voltage Display: > ±5% of reading ±2 counts
Measurement Stability
±10 counts
Automatic Shutoff
Unit will shut off after 20 minutes after last switch activity
Power Requirements
One (1) 9V alkaline battery
Operating Time
Greater than 50 hours, with new battery at 21°C
continuous usage
Operating Conditions
Temperature: 10-30°C
Relative Humidity: Up to 80%, non-condensing
Altitude: Up to 2,000 meters
Dimensions
0.94" H x 2.75" W x 4.94" L
(23.9mm H x 69.9mm W x 125.5mm L)
Weight (with battery)
4.9 oz
(153 g)
Voltage Monitor Connection
2.5mm audio jack
CE Certied
Figure 8. Taking decay measurements
Maintenance
The Digital Static Field Meter is factory calibrated and no
maintenance is required. If for any reason you believe
the Meter is not working correctly, please contact Desco
Customer Service. CAUTION - There are no user
serviceable parts. Any unauthorized service will void the
warranty and result in additional repair charges.
Note: This Meter is a precision instrument and should
not be subjected to dropping as that would void the
warranty.
BATTERY REPLACEMENT
The Digital Static Field Meter operates from a standard
9 VDC alkaline battery. Battery life is in excess of 50
hours under normal use. When the battery voltage
drops below 6.5 V, “BAT” will appear on the display. To
change the battery, slide the battery cover down at the
back of the Meter and remove the battery from the
battery clip. Replace the battery with a fresh one and
reinstall the battery cover. The battery should be
removed from the Meter if its is to be stored for an
extended period of time.

DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • [phone] • Fax [phone]
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • [phone] • Fax [phone] • Website: Desco.com
TB-3041 Page 6 of 6 © 2009 DESCO INDUSTRIES, INC.
Employee Owned
Limited Warranty
Desco expressly warrants that for a period of one (1) year from the
date of purchase Desco Ionization Test Kits will be free of defects
in material (parts) and workmanship (labor). Within the warranty
period, a credit for purchase of replacement Desco Ionization Test
Kits, or, at Desco’s option, the Ionization Test Kit will be repaired or
replaced free of charge. If product credit is issued, the amount will
be calculated by multiplying the unused portion of the expected one
year life times the original unit purchase price. Call our Customer
Service Department at 909-627-8178 (Chino, CA) or 781-821-8370
(Canton, MA) for a Return Material Authorization (RMA) and proper
shipping instructions and address. Please include a copy of your
original packing slip, invoice, or other proof of date of purchase. Any
unit under warranty should be shipped prepaid to the Desco factory.
Warranty replacements will take approximately two weeks.
If your unit is out of warranty, call our Customer Service Department
at 909-627-8178 (Chino, CA) or 781-821-8370 (Canton, MA) for a
Return Material Authorization (RMA) and proper shipping instructions
and address. Desco will quote repair charges necessary to bring
your unit up to factory standards.
Warranty Exclusions
THE FOREGOING EXPRESS WARRANTY IS MADE IN LIEU
OF ALL OTHER PRODUCT WARRANTIES, EXPRESSED AND
IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR A
PARTICULAR PURPOSE WHICH ARE SPECIFICALLY
DISCLAIMED. The express warranty will not apply to defects or
damage due to accidents, neglect, misuse, alterations, operator
error, or failure to properly maintain, clean or repair products.
Limit of Liability
In no event will Desco or any seller be responsible or liable for any
injury, loss or damage, direct or consequential, arising out of the use
of or the inability to use the product. Before using, users shall
determine the suitability of the product for their intended use, and
users assume all risk and liability whatsoever in connection
therewith.
CHARGER
Output
1100 VDC nominal, < 5 μA max
Output Terminal
Banana / Acorn assembly
Power Requirements
One (1) 9V alkaline battery
Operating Conditions
Temperature: 10-30°C
Relative Humidity: 10-80%, non-condensing
Dimensions
4.5" L x 2.6" W x 1.1" H
(114.3mm L x 66.0mm W x 27.9mm H)
Weight (with battery)
4.9 oz
(153 g)
CE Certied
CONDUCTIVE PLATE
Plate Capacitance
13 pF (± 2 pF)
Range
0 to ± 2 kV
Weight
2.4 oz
(75 g)