Static Electricity 2000 Edition

D.1.6 Charge Decay Time.
The time for static electric charge
to be reduced to a given percent of the charge’s original level.
D.1.7 Charge Density.
The charge per unit area on a surface
or the charge per unit volume in space. Surface charge density
is measured in coulombs per square meter. Volume charge
density, also called space charge density or space charge, is
measured in coulombs per cubic meter.
D.1.8 Charge Relaxation.
The process by which separated
charges recombine or excess charge is lost from a system.
D.1.9 Charging Current (I
c
).
The rate of flow of charge into a
given system per unit of time, expressed in amperes.
D.1.10 Charging, Field.
Charging of particles in an electric
field as the result of ions from a corona or other source; also
known as ion-bombardment charging. The maximum charge
that a particle can gain by field charging is proportional to the
cross-sectional area of the particle and the strength of the elec-
tric field. Field charging is a dominant particle-charging
mechanism for particles larger than a few tenths of a micron.
D.1.11 Charging, Induction.
The act of charging an object by
bringing it near another charged object, then touching the
first object to ground; also known as induction. Charge polar-
ization is induced on a grounded object in the vicinity of a
charged surface due to the electric field existing between the
object and the surface. If the ground connection is removed
from the object during this period, the induced charge
remains on the object. Induction charging will occur when a
Typical grounding clamp
with recoiling cable
Typical pipe grounding
jumper at swivel connections
Track
connection
Grounding “bus” (typical)
Ground rod
Note: Any conductive
level measuring device
or pipe should be
grounded before inserting
into any car or truck.

---

77–
52
STATIC ELECTRICITY
2000 Edition
person walks from a conductive floor covering onto an insulat-
ing floor in the presence of an electric field.