Table of Contents
Advertisement
341
343A
above
the meter.
The
lamps
are easily
removeable without
special tools.
The two
control
circuit
lamps,
DS1
and
DS2
are
located
on
the
main
circuit
board and
are accessible
after
removing
the
top
cover.
4-24.
PERFORMANCE
TESTS
4-25.
Performance
tests consist
of
line
regulation,
load
regulation,
ripple,
and
output
voltage
accuracy
tests,
and
are
designed
to
compare
instrument
performance
to
speci-
fications.
The
tests
may
be
used during
maintenance
or
for
receiving inspection.
Test should be
performed under
standard
test
conditions:
ambient temperature 23
±
1°
C,
relative
humidity
less
than 70%. Allow instrument
to
warm
up
for at
least
1
hour
before
testing.
An
instrument
that
fails
any
of
the
performance
tests
may
require corrective
maintenance
or
calibration.
In
case
of
trouble, analysis
of
the
tests
results,
with
reference to the
troubleshooting
section,
should help to
locate the trouble.
NOTE!
Unless otherwise
specified,
the
following
tests
apply
to
both
Model
341
A
and Model
343A
instruments.
4-26.
LINE
REGULATION
4-27.
The
line
regulation
test
determines
whether
the
output
voltage
of
the instrument
will
remain
constant,
within
specified
limits,
for
low and
high
line
voltages.
a.
Connect
the
autotransformer
to the
line,
and connect
the
Model 341
A
to the
autotransformer.
Adjust the
autotransformer
for
1
15 volts
output.
b.
Set
the
Model
341
A/343
A
controls
as
follows:
FUNCTION
STANDBY/RESET
e.
Vary
the
line
voltage
from
115
volts to
103.5
volts.
The 895
A
should
indicate a voltage
change of
less
than
30
microvolts.
f.
Vary
the
line
voltage
from
1
15
volts
to 126.5
volts.
The 89
5
A
should
indicate
a
voltage
change of
less
than
30
microvolts.
g.
Repeat
steps c
through
f
with
loads
and
instrument
settings as
follows.
The
maximum
voltage
changes
should
be
as
indicated.
LOAD
RANGE VOLTAGE
DIALS
MAXIMUM
VOLTAGE
CHANGE
400
ohms
±6%
10
10.00000
(341
A)
75
uv
1
w
10.000000 (343A)
4k
±5%
100
100.0000
(341 A)
525
uv
10
w
100.00000 (343
A)
40k
±5%
1000
1000.000
(341
A)
5
mv
50
w
1000.0000 (343A)
FAULT
ANALYSIS
If
the
line
regulation
is
not within
limits,
it is
likely
that
the
chopper
amplifier or preampli-
fier
gain
is
too
low.
Check
chopper
amplifier
performance
as
described
in
paragraph
447.
Check
test
point
8 (TP
8
)
voltages
in
the
pre-
amplifier
as
described
in
paragraph
4
45.
4-28.
LOAD REGULATION
4-29.
The
load regulation
test
determines
if
the
instru-
ment
output
voltage
will
remain
constant, within
specified
limits,
under
no-load
to
full-load
conditions.
RANGE
Voltage
Dials
CURRENT
LIMIT
10
1.00000 (Model 341
A)
1.000000 (Model 343
A)
Fully clockwise
a.
Connect
the
autotransformer
to
the
line,
and
connect
the
Model
341
A/343
A
to the autotransformer.
Ad-
just
the
autotransformer
for
1
1
5 volts
output.
b.
Set
the
Model
341A/343A
controls
as
follows:
c.
Connect
a
40
ohm ±
5%
5
1/2
watt
resistor
to the
Model
341A/343A
OUTPUT
terminals.
d.
Connect
the
895A
differential
voltmeter
to
the
OUTPUT
terminals,
and
set
the
FUNCTION
switch
to
ON.
FUNCTION
STANDBY/RESET
RANGE
Voltage
dials
CURRENT
LIMIT
10
1.00000 (Model 341
A)
1.000000 (Model
343A)
Fully clockwise
4-6
Advertisement
Table of Contents
