GENERAL RADIO COMPANY 1650-B Instruction Manual page 13

I
i
i
* -
LOW D 1 0 TO I1
%y
. . .
cxpKj
o
UNKNOWN HIGH
&As
opt-
T,?
T I P + BODY
ARM
'"
Do0\
( 1
hn
cGRL
RHEOSTAT
0 1 p F
C A S E
c,
;
c,
b,O
<
Dx
U R ~ C ~ v R T C T
a. Turn GENERATOR switch t o
B A T CHECK position. If the meter
pointer i s not i n the B A T sector,
replace the batteries.
b. Turn GENERATOR switch t o AC
E X T E R N A L or AC
INTERNAL
1 kHz.
c. Turn PARAMETER switch t o Cs.
d.
Connect the unknown so that
most stray capacitance i s between
the LOW terminal and the
1650-8
case.
e. Turn
ORTHONULL@
switch t o
OUT.
f.
Turn OSC L E V E L clockwise.
The panel control affects only the
internal osci llator.
g. Turn DQ d i a l near 0.05 on the
LOW
D
scale.
h.
Turn CGRL d i a l near
11.
i.
Adiust D E T SENS for about
6
divisions deflection.
i.
Turn M U L T I P L I E R switch for
minimum meter reading.
k.
Alternately adiust, f i r s t the CGRL
dial, then the DQ d i a l for the best
null, increasing the D E T SENS as
needed.
I, ORTHONULL@
i s not used on
t h i s bridge unless the DQ d i a l read-
ing times f(kHz) approaches or ex-
ceeds 1.
m. If the DQ d i a l goes into the
uncalibrated portion, the unknown
should be measured as
Cp.
n. The series capacitance of the
unknown equals the product of the
CGRL-dial reading and the
MUL-
T I P L I E R - s w i t c h setting.
o,The D equals the reading on the
DQ d i a l times f (kHz).
p. Turn GENERATOR switch t o OFF.
HIGH 0 ( 0 I TO 5 0 )
O l i F
C, $ C T
6- 8
D L -
'
" R X C X v R T C ,
a. Turn GENERATOR switch t o
BAT
CHECK position.
If
the meter
pointer i s not i n the B A T sector,
replace
the batteries.
-rum
GENERATOR switch
to
AC
E X T E R N A L or AC I N T E R N A L
1
kHz.
c. Turn PARAMETER switch t o Cp.
Large electrolytics should be mea-
sured at a low frequency (120 Hz)
for greater accuracy.
d.
Connect the unknown so that
most stray capacitance i s between
the LOW terminal and the 1650-8
case.
e. Turn
ORTHONULL@
switch t o
OUT.
f.
Turn OSC L E V E L clockwise.
The panel control affects only the
internal oscillator.
g. Turn DQ d i a l near
0.2
on the
HIGH
D
scale.
h.
Turn C G R L d i a l near 11.
i . Adiust D E T SENS for about
6
divisions deflection.
i.
Turn M U L T I P L I E R switch for
minimum meter reading.
k.
Alternately adiust, f i r s t the DQ
dial, then the CGRL d i a l for the
best null, increasing the D E T
SENS
as needed.
I. ORTHONULL@
switch should be
set t o I N i f the D Q d i a l reading
times l / f (kHz) approaches or ex-
ceeds 1.
m.
If
the DQ d i a l reaches the stop
at 0.1, the unknown should be mea-
sured as Cs.
n. The parallel capacitance of the
unknown equals the product of the
,
CGRL-dial reading and the MUL-
T I P L I E R - s w i t c h setting.
o. The D equals the reading on the
DQ
d i a l times
l / f
(kHz).
p. Turn GENERATOR switch OFF.
- -
R
IN. OC
e-o
UNKNOWN
o
HIGH
loon
+ 6 VOLTS
(1
ARM o p p
RHEosTaT
cGRL
( t i 10 kn
a,#
E
E x T
oc
cbsc
Rrxr 2 1 ~ 1 ~
, $ ,
VOLT&dE
@ =
E ;
UNKNOWN
o
HIGH
T , P *
BlbS
OPP
BWI
50kn ARM
CGRL
( # i n
RHEOSTAT
1 0 k n
a =
w
C L I E
A c
1:
UNKNOWN
o
HIGH
BOD"
-
ARM o p p
CGRL
'Ihn
RHEOSTAT
1 0 k n
a%L
R * R ~ a,&
0
R x
7
a. Check mechanical zero of meter.
b. Turn GENERATOR switch t o the
B A T CHECK position. I f the meter
pointer is not i n the B A T sector,
replace the batteries.
c. Turn GENERATOR switch t o the
desired generator source. The
OSC
L E V E L control affects only the
internal osci
l
lator.
d.
Turn
ORTHONULL@
switch to
OUT and PARAMETER switch t o R.
e. Turn CGRL d i a l near
11.
f.
Adiust D E T SENS control for
about
6
divisions deflection.
g. Turn M U L T I P L I E R switch for
minimum reading t o the left of
center
i f
making a dc measurement.
N u l l as usual i f making an ac mea-
surement. (DQ rheostat not i n the
circuit.)
h.
Adjust C G R L d i a l for best ac
null, or zero the pointer
if
using
dc.
If
ac n u l l i s not sharp, a re-
active balance may be necessary,
see instruction manual.
i.
The unknown resistance is the
CGRL-dial reading multiplied by
the M U L T I P L I E R switch setting.
i.
Turn GENERATOR switch t o
OFF.