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341
343A
c.
Jumper
the
SENSE
terminals to the
output
terminals.
d.
Connect
the
895
A
differential
voltmeter
to
the
SENSE
terminals,
and
set
the
FUNCTION
switch to
ON.
e.
Record
the voltage indicated
by
the
895
A.
l.
Connect
a
40k ±5%,
50 watt
resistor
to
the
OUTPUT
terminals.
The
895
A
should
indicate
a
voltage
change
of
less
than
5 millivolts.
m.
Repeat
steps
a.
through
m.
for
line
voltages
of
103.5
volts
ac
and
126.5
volts
ac.
f.
Connect
a
40
ohm
±5%,
1/2
watt
resistor
to the
OUTPUT
terminals.
The
voltmeter should
indicate
a
voltage
change of
less
than
30
microvolts.
g.
Remove
the
40
ohm
resistor,
and
set
the voltage
dials
to
10.00000 (10.000000
for the
Model
343A).
Record
the voltage indicated
by
the
895
A.
h.
Connect
a
400
ohm
±5%,
1
watt
resistor
to the
OUTPUT
terminals.
The 895
A
should
indicate a
voltage
change of
less
than
75
microvolts.
i.
Remove
the
400
ohm
resistor.
Set the
RANGE
switch to
100
and
the voltage
dials
to
100.0000
(100.00000 on Model 343A).
Record
the voltage
indicated
by
the
895A.
j.
Connect
a
4k ± 5
%,
10 watt
resistor to
the
OUTPUT
terminals.
The
895A
should
indicate a voltage
change
of
less
than
525
microvolts.
k.
Remove
the
4
k
resistor.
Set the
RANGE
switch
to
1000
and
the voltage
dials
to
1000
.Q00
(1000.0000
on
the
Model 343
A).
Record
the voltage indicated
by
the
895
A.
FAULT
ANALYSIS
If
load
regulation
is
poor,
check
for
proper
operation
of
the
preamplifier
and chopper
amplifier
as
described
in
paragraph 4-45
and
4-47.
Also, ensure
that
SENSE
terminals are
connected
properly. See
paragraph
2-14.
4-30.
RIPPLE
4-31.
The
ripple
test
determines
if
the ac ripple
present
on
the
instrument dc output
is
within
specified
limits.
a.
Install
top
and bottom
instrument
covers,
and
con-
nect
+
OUTPUT
to chassis
ground.
b.
Connect
the preamplifier to the
OUTPUT
terminals,
and
connect
the
93 IB
true
rms
voltmeter
to the
output of
the preamplifier.
c.
Set
the
FUNCTION
switch
to
on,
and
set
the
RANGE
switch
and
voltage
dials as
shown
in
Figure
4-5.
The rms
ripple
should not exceed the
values
shown.
RANGE
VOLTAGE
DIALS
MAXIMUM
RIPPLE
115
VAC
50-60
HZ
LINE
115
VAC
400
HZ
LINE
341A
343A
341
A
/
343
RMS
P-P
RMS
EBB
RMS
P-P
10
10.00000
{341
A)
100
uv
1
mv
50
uv
400
uv
100
uv
2
mv
10.000000 (343A)
100
100.0000
(341
A)
100
uv
1
mv
50 uv
400
uv
100
uv
2
mv
100.00000
(343
A)
1000
1000.000
(341
A)
100
uv
1
mv
50
uv
400
uv
100
uv
2
mv
1000.0000 (343A)
Figure
4-5.
RIPPLE
SPECIFICATIONS
4-7
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