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Section
III
Model 4342A
Parallel
Connection
Measurements
g.
h.
1.
j.
k.
1.
3-22
Depress
AQ button
and adjust
AQ ZERO
(COARSE and FINE)
controls
so that
meter
pointer
indicates
zero
(full
scale)
on AQ scale.
Note
Press AQ button
to release
AQ func-
tion
and recheck
for
current
reso-
nance.
Again
depress
the
AQ button
and recheck
for
AQ zero indication.
Place
the
sample
material
between
1645lA
electrodes.
The sample
mate-
rial
should
be in close
contact
with
electrodes.
Note
164SlA micrometer
reading
TX (as thickness
of the
sample).
Again
adjust
the L/C and AC dial
con-
trols
for
resonance.
Note
sum of the
C dial
and AC dial
readings
as C3 and
panel
meter
AQ reading.
If
meter
pointer
scales
out
at the
left
end of
the
scale
(AQ full
scale),
reset
the
function
for
normal
Q measurement.
The difference
in Q is calculated
from
the
two Q values
as AQ = Q2 - 93.
Remove the
sample material
from be-
tween
the
1645lA
electrodes.
Let
the
L/C and AC dial
settings
remain
as is,
and reduce
space between
the
1645lA
electrodes
until
resonance
again
occurs.
Note
the micrometer
reading
as To.
Note
If
this
procedure
is a little
diffi-
cult,
let
the distance
between
the
16451A electrodes
remain
the
same as
the
thickness
of the
sample being
measured
and take
resonance
again
by adjusting
the
L/C and AC dial
controls.
Note
sum of the
C and
AC dial
readings
as CI,.
Calculation
formulas
of the
dielectric
constant,
dielectric
loss,
and asso-
ciated
measurement
parameter
values
are
summarized
below:
Specific
inductive
capacity
of the
sample
material
is:
Es =
TX
To
. . . . . . . . . . . . . . . . (eq.
3-29)
Dielectric
constant
of the
sample
material
is:
E
=
EO'ES
TX
= -
x
8.85
x lo-"
(F/m)
To
. . . . . . . . . . . . . . . (eq.
3-30)
Electrode
capacitance
with
the
sample
material
is:
cx = +
(PF)
=
c4 - c3 + &
(PF) . . (eq.
3-31)
Where,
the
unit
for
TX and To is cm.
Equivalent
parallel
conductance
of the
sample material
is:
Gx = 2TrfC1
Qz (Qz- AQ)
..(eq.
3-32)
Dielectric
loss
angle
(dissipation
factor)
of
the
sample material
is:
tand
= Cl . To
AQ
Q2(Q2 -
AQ>
Cl
AQ
= ??c ' Q2(Q2 - AQ)
= Gx/2nfCx
. . . . . . . . . . . (eq.
3-33)
Where,
f is measurement
frequency.
Note
%2?
may be used instead
of
AQ
Q2(Q2 -
AQ)
in equation
3-33.
Q value
of the
sample
material
is:
Qx = l/tan
B . . . . . . . . . . . . . . (eq.
3-34)
Note
The theoretical
formula
for
1645lA
electrode
capacitance
is:
c =
s x1o-2
(F) =
'
(PF)
36.~1 xlOg xTo
3.6~ To
where
S is area
of electrode
(cm2).
Since
the
size
of the
electrode
is
3.8cm in diameter,
C aboke
can be
shown to be l/To
(pF).
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