ESI 250-DA - Extending D and Q Ranges with External Rheostat (Capacitors); Series Capacitance Measurement with External Q Rheostat

2.4.8
TO
USE
AN
EXTERNAL D-Q
RHEOSTAT
The
D
and
Q
ranges
of
the
bridge
can
be
extended by
use of
an
external
rheostat*
The
curve
below
shows
the
ranges
of
D
and
Q
for which this technique
is
advisiable.
0.01
lOKCl
I.OKC
>
o
z
Ui
3
o
UJ
O.IKC
0,01 KC
STORAGE
FACTOR
(Q)
0.1 1.0 10
100 1000
10,000
100 10
1.0
0.1
O.Ol
0.001
0.0001
DISSIPATION
FACTOR
(0)
SET
THE
CIRCUIT
SELECTOR TO This
bridge
circuit can
be
used
for
C
SERIES
both
series
and
parallel
connections
when
using
an external
D-Q
rheostat.
2.
4.
8. 1
SERIES CAPACITANCE
BRIDGE
REPLACE THE EXT D-Q
JUMPER
BY
AN EXTERNAL RHEOSTAT
"R".
UNKNOWN
CAPACITOR
This
completes
the
capacitance
circuit series
.
BALANCE
THE BRIDGE, Use the range
switch, the
MAIN
DIALS
and the external
rheostat.
READ
Cg (EQUIVALENT
SERIES
This
reading
does
not
depend on
CAPACITANCE) FROM
THE
DIALS.
frequency.
Dissipation
factor
in
per
unit
Frequency
in
kilocycles
External
D-Q
rheostat
resist-
ance
in
kilohms,
D-Q
dial
reading
in
divisions
CALCULATE D
D
=
0.628
^
^dial reading
1
D
'kc
kc
D
dial
lelslil
250-DA
t/59