Agilent Technologies 4349B User Manual

4349B
Contact
check
feature
The
contact
check
feature
of
the
4349B
measures
the
capacitance
of the
DUT using
a 480-kHz
ac
signal
(OSC1)
and
makes
the
judgment of
Contact/NO Contact
from whether
the result
is
greater
than
the
limit
vale
. The
limit value
used for
the judgment
is determined
by the
following
equation
using
the
capacitance
in
the Open
state (Cs)
measured when
the Open
correction
was
executed.
Limit
=
Cs*1.035+0.40*10E-12+oset
Where
oset
is
any
value
the
user can
set. Usually
set it
to 0
(default
value).
F
or
the
4349B
,
when
measuring capacitance
in the
contact check
and the
Open
correction,
an
ac
signal
with
the
same
phase as
OSC1 is
applied from
OSC2 to
the
inner
shield
to
reduce
the
eect
of
C1
and
C0.
However
,
because it
is impractical
to apply
an
ac
signal
with
the
completely
same
phase
to
both the
core wire
and the
inner
shield
considering
the
input
resistance
(1k)
of
the
ammeter,
some residual
capacitance is
observed.
Especially
when
the
coaxial
extension
cable
is
long, this
residual capacitance
becomes larger
.
Figure
3-8.
The
contact
check
is
performed
at
the
following
timing.
Figure 3-9.
Function Reference 3-21

Agilent Technologies 4349B Specifications

General

Brand	Agilent Technologies
Model	4349B
Category	Measuring Instruments
Language	English