Desco 19492 Operation And Maintenance

Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176 - TestEquipmentDepot.com
Digital Static Field Meter
Operation and Maintenance
Figure 1. Desco 19492

Description

The Desco Digital Static Field Meter is a high quality,
portable non-contacting static field meter which
consistently produces accurate readings with ease and
provides years of trouble-free operation.
The Digital Static Field Meter indicates surface voltage
and polarity on objects up to ±19.99 kV at a distance of
1 inch with an accuracy of ±5% of the displayed value. It
is chopper-stabilized for use under almost any condition
including ionized environments. The conductive case
and ground snap facilitate grounding for accurate
measurement. Also featured are a zero button and a
display hold function. A unique LED rangefinder
system provides accurate positioning of the Meter from
the target.
Rev. June 2009
TB-3040 Page 1 of 6
TECHNICAL BULLETIN TB-3040
Digital Static Field Meter
Its accuracy is dependent upon three factors:
• Grounding of the Meter via a ground cord (not
included) (Meter is also grounded when held by a
grounded operator).
• The instrument must be properly zeroed.
• The distance from the front edge of the case to the
target or surface under examination must be
accurately defined.
Charged insulators in the ESD protected area can
adversely impact quality, productivity, and reliability.
"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)
Compliance verification should include periodic checks
with a static field 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 field-induced CDM (Charged Device
Model) damage, the ESD program shall include a plan
for the handling of process-required insulators. If the
field 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 or replace with a static
control protective version of the item.
Made in America
© 2009 DESCO INDUSTRIES, INC.
Employee Owned