TECHNICAL BULLETIN TB-3040
Digital Static Field Meter
Operation and Maintenance
Made in the
United States of America
“When any object becomes electrostatically charged,
there is an electrostatic field associated with that charge.
If an ESDS (ESD sensitive) device is placed in that
electrostatic field, 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 field and grounded
again, a second CDM event will occur as charge (of
opposite polarity from the first event) is transferred from
the device.” (Handbook ESD TR20.20 section 2.7.5 Field
Induced Discharges)
“All nonessential insulators such as coffee cups, food
wrappers and personal items shall be removed from the
EPA.
The ESD program shall include a plan for handling
process-required insulators in order to mitigate
field-induced CDM damage.
If the field measured on the process required insulator
is greater than 2000 volts/inch and the process required
insulator is less than 30 cm (12 inches) from the ESDS
item, steps shall be taken to either:
A) Separate the required insulator from the ESDS item
by a distance of greater than 30 cm (12 inches); or
Figure 1. Desco 19492 Digital Static Field Meter
B) Use ionization or other charge mitigating techniques
to neutralize the charge.
Description
If the field measured on the process required insulator
is greater than 125 volts/inch and the process required
insulator is less than 2.5 cm (1 inch) from the ESDS
item, steps shall be taken to either:
The Desco Digital Static Field Meter indicates surface
voltage and polarity on objects. The meter can measure
ranges of 0 to ±1.999 kV or 0 to ±19.99 kV at a distance
of 1 inch with an accuracy of ±5% of the displayed
value. The automatic zero button allows adjustment to
zero with no screws or dials to turn. The hold button
allows the user to “freeze” a displayed measurement
for evaluation. A LED range finder helps the operator to
place the meter at the correct distance from the surface
being measured. The meter will automatically turn off
after 20 minutes to conserve battery power (9V). The
Digital Static Field Meter is calibrated with accepted
procedures and standards traceable to the National
Institute of Standards and Technology.
A) Separate the required insulator from the ESDS item
by a distance of greater than 2.5 cm (1 inch); or
B) Use ionization or other charge mitigating techniques
to neutralize the charge.
NOTE: The accurate measurement of electrostatic fields
requires that the person making the measurement is
familiar with the operation of the measuring equipment.
Most hand held meters require that the reading be taken
at a fixed distance from the object. They also normally
specify that the object has a minimum dimension of
fixed size in order to obtain an accurate reading.” (ANSI/
ESD S20.20-2014 section 8.3.1 Insulators)
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3040 Page 1 of 5
April 2018
© 2018 DESCO INDUSTRIES, INC.
Employee Owned
Packaging
D. HOLD Button: Press to freeze the reading on the
display. Press again to return to normal measurement
operation.
1 Digital Static Field Meter
1 9V Alkaline Battery
1 Certificate of Calibration
E. Battery Cover: Slide the cover down to open the 9V
battery compartment.
Features and Components
Operation
Note: The 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 wearing
a wrist strap and grounded to achieve more accurate
measurements.
C
D
A
B
FRONT VIEW
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
Place the meter 1 inch from the object to be measured.
This distance is measured from the front edge of the
meter case to the surface of the object. The meter now
displays a reading (from 0 to ±.200 or ±2.00) of the
electrostatic field in kilovolts per inch.
E
BACK VIEW
Figure 2. Digital Static Field Meter features and
components
A. POWER Button: Press to turn the unit ON and OFF.
B. RANGE / ZERO Button: Press to select the
measurement range. Press and hold to zero the meter.
C. Analog Output Jack: A low-voltage signal of the
measured voltage is provided at this output. The voltage
is 1/1000th (±2 kV range) or 1/10,000 (±20 kV range) of
the measured voltage.
Note: The red ranging lights are provided to help place
the meter at the correct distance from the object. The
lights are set to produce a concentric red bullseye
pattern on a flat opaque surface 1 inch from the front
edge of the meter. This can be practiced by aiming the
meter at a sheet of white paper.
The display will indicate “1” or “-1” when the meter is
over-ranged. Change the range of the unit if necessary.
If the measurement exceeds 20 kV, move the meter
farther away from the object and multiply the reading
by the distance (in inches) away from the object being
measured. The measurement accuracy is dependent on
a stable ground reference and the 1 inch measuring
distance. It is also dependent on the “aspect ratio”,
relating the size of the object to be measured to the
measurement distance.
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3040 Page 2 of 5
© 2018 DESCO INDUSTRIES, INC.
Employee Owned
Thousands
Hundreds
Tens
HOLDING THE LAST READING
With the meter positioned 1 inch from the object being
measured, press the HOLD button. This will 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.
Note: The red ranging lights will be off while the meter is
in HOLD mode. It is advised to do this between
measurements to prolong battery life.
Figure 3. Reading the Digital Static Field Meter while in
the ±20 kV range
Hundreds
Tens
Ones
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. The voltage at
this output is 1/1000th (±2 kV range) or 1/10,000 (±20
kV range) of the measured voltage. Contact Customer
Service for more information.
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.
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.
Figure 4. Reading the Digital Static Field Meter while in
the ±2 kV range
Note: This Meter is a precision instrument and should
not be subjected to dropping as damage would not be
covered by the limited warranty.
Note: This aspect ratio should be at least 3 for best
accuracy, i.e. the object should be at least a 3 inch
square when measuring at a 1 inch 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, multiply the meter reading by 3 to
give a range of 0 to 60 kilovolts. For accuracy, the object
being measured at this distance should be at least a 9
inch square.
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3040 Page 3 of 5
© 2018 DESCO INDUSTRIES, INC.
Employee Owned
Specifications
General
Performance
Measurement Range (switch selectable)
Low Range
0 to ±2kV / inch
High Range
0 to ±20 kV / inch
Measurement Accuracy
Voltage Monitor Output Better than ±5% of reading,
10mV
Better than ±5% of reading,
±2 counts
Voltage Display
Measurement Stability
±10 counts
Voltage Monitor
Output
2 volts output at full scale
High Range
1/1000 of the measured
electrostatic field
1/10000 of the measured
electrostatic field
Front Panel Meter
Voltage Display
0.9" H x 2.8" W x 4.9"L
(24 mm x 70 mm x 126 mm)
Weight
4.9 oz. (140 g) with battery
Voltage Monitor
Connection
2.5 mm jack (3/32")
monophone
Tip
Signal
Sleeve
Ground
Operating Conditions
Temperature
50 to 86ºF (10 to 30ºC)
Relative Humidity
To 80%, non-condensing
Altitude
To 2000 m
Certifications
CE
Power Requirements
Ratio
Low Range
Dimensions
3-1/2 digit LED display
Range
Low
0 to ±1.999 kV / inch
High
0 to ±19.99 kV / inch
Power
One (1) 9-volt alkaline battery
Operating Time
Greater than 50 hours,
with a new battery at 21ºC
continuous
Power Switch
A membrane switch that
is designed to prevent
accidental turn on. Powers
the instrument on and off.
Display Resolution
Low Range
1 V / inch
High Range
10 V / inch
Sampling Rate
3 readings per second
Features
Automatic Shutoff
Unit will shut off after 20
minutes from last activity
Ranging System
LED distance indicator;
aligned targets indicate one
(1) inch
Range / Zero Switch
LED distance indicator.
Resets the instrument to zero
and selects the measurement
range.
Low Battery Indicator
An LCD display message
indicates when the battery is
low
Hold Switch
Retains the LCD display
reading when depressed
DESCO WEST - 3651 Walnut Avenue, Chino, CA 91710 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3040 Page 4 of 5
© 2018 DESCO INDUSTRIES, INC.
Employee Owned
Ionization Test Kit Accessories
Desco offers accessories for the Digital Static Field
Meter designed to facilitate routine auditing and periodic
testing of ionization equipment (Ref: ANSI/ESD SP3.3).
The Meter and accessories combination can be used to
test an ionizer’s overall performance. This highly
portable test kit allows the user to make quick and
accurate offset voltage balance level and neutralization
discharge time measurements (counting or using a
stopwatch). These accessories are available as Desco
item 19440 Test Kit Upgrade which includes the
Conductive Plate and Charger.
Limited Warranty, Warranty Exclusions, Limit
of Liability and RMA Request Instructions
See the Desco Warranty Desco.com/Limited-Warranty.aspx
Figure 5. Installing the 19441 Conductive Plate
18"
12"
Figure 6. 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 • (909) 627-8178
DESCO EAST - One Colgate Way, Canton, MA 02021-1407 • (781) 821-8370 • Website: Desco.com
TB-3040 Page 5 of 5
© 2018 DESCO INDUSTRIES, INC.
Employee Owned
