PGA-710 Autoanalysis System – How To Measure Guide
21
f.
The Operator may enter comments,
references, testing notes, etc., into any
report by selecting the
Document
drop
down menu and clicking on
Remarks
.
The Remarks window will open.
Overview: Body Voltage Generation Analysis
ESD Analysis applications may require one to know how quickly electrostatic voltage will
dissipate from a material, object or body when grounded, or exposed to ionized air. The
process of measuring the time required for a defined voltage to dissipate is often referred to as
“decay time”, i.e. determining how many seconds, or fractions of a second, are required for a
voltage to dissipate from one magnitude to a defined lower level.
Decay analysis is often used for evaluating and auditing ionizing devices such as bench top
units, compressed air ionization nozzles for removing particulate, and room ionization systems.
A voltage is applied to a floating plate of a Charged Plate Monitor (CPM), which is positioned in
the ion field or air flow. The time required in seconds for the ionizer to reduce that voltage to a
predetermined level is measured. Decay analysis may also be used to evaluate various
packaging materials and configurations. One may wish to measure how quickly a charge is
dissipated from a person when grounded, or when wearing ESD footwear and stepping onto a
floor surface.
The PGA-710 Autoanalysis System was originally designed primarily for ionization decay
analysis. However, other decay analysis applications are apparent. The following illustrations
focus on measuring decay time of a bench top ionizer. The principles apply to many other
evaluations and measurements where the voltage change over time is an important
measurement. For detailed information regarding Standard Test Methods and Standard
Practices for evaluating and auditing ionizers and devices refer to ESD Association’s
documents:
ANSI-ESD-STM3.1-2000
Ionization
and
ESD-SP3.3-2000
Periodic Verification of Ionizers
Figure 35: Opening Remarks Window in a Test
Report
Figure 36: Optional Fourth Page of Body
Voltage Report Documents Operator’s
Comments
