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Section
IV
Model
.1455A
4-41.
The
DC
Transfer
Standard
required
for the
following
test
must
be
calibrated to
a
1.
017
V
to
1.019
V
standard
cell
that
has
been
calibrated
by
the
National
Bureau of Standards (NBS).
If
the
3435A
is
to
be
tested
for
its
24-hour accuracy
specifications,
the
Transfer
Standard must be
adjusted
for
optimum
1-volt
and
10-volt
output accuracy
using NBS-calibrated
stan-
dards.
It
is
recommended
that
the
Transfer
Standard
be
calibrated
and
adjusted
just
prior to
use.
After
calibra-
tion,
it
should be
left
on
and.
if
possible,
kept
in
a
con-
trolled
environment where
the
ambient temperature
is
within
one
or
two
degrees
of
the
temperature
in
which
it
was
calibrated.
The
following
procedure should
be
per-
formed
in
that
same
environment.
4-42.
If
the
recommended
DC
Transfer
Standard
or
its
equivalent
is
not
available,
an NBS-calibrated standard
cell
(1.017
V
to 1.019
V) can be
substituted.
If this
is
done, check
the
full-scale
accuracy of
the
34S5A
1
V
and
10
V
ranges using the Reference Divider
recommended
in
the
procedue.
443.
Test Proeadurt.
Equipment
Required:
Reference
Divider (Fluke
Model 7S0A)
DC
Transfer
Standard
(Fluke
Model
731A)
DC
Standard
(Systron
Donner Model
M106A)
DC
Null Voltmeter
(-hp-
Model 419A)
a.
Set the
34S5A
controls
as follows:
FUNCTION
DCV
RANGE
1
V
HIGH RESOLUTION
OFF
AUTO CAL
ON
GUARD
ON
TRIGGER
INTERNAL
b.
Set the
DC
Transfer
Standard
for
an output of
I
V.
Connect
the
output
of
the transfer
standard
to the
3455A
INPUT.
c.
The 3455A
reading
should be
within the
test
limits
listed
in
Table
4-9,
verifying
its
1-volt full-scale
accuracy
with
High
Resolution
off.
Tabla
4-8.
DC
Accaracy
Test
(1
V,
10
V
Fall-Seala;
High
Ratolutian
Off).
Input
34SSA
24
Hour
90
Oey
Level
Renge
Test
Limits
Limits
1
V
1
V
0.99996
to
1.00004
0.99993
to
1.00007
10
V
10
V
9.9997
to
10.0003
9.9994
to
10.0006
d.
Set the
3455A
HIGH RESOLUTION
to
ON.
The
345SA
reading should
be
within
the
test
limits
listed in
Table
4-10, verifying
its
1-volt
full
scale
accuracy with
High
Resolution on.
e.
Set the
3455A
RANGE
to
10
V.
Set the
Transfer
Standard
for
an output of
10
V.
The 345SA
reading
should be
within the
test
limits listed in
Table
4-10,
veri-
fying
its
10-volt
full
scale
accuracy with
High
Resolu-
tion
on.
Table
410.
DC
Aearaey
Teat
(1
V.
10
V
Full
Stale;
High
Retalulian
On).
.evel
Renge
24
Hour
Test
Limits
90
Dsy
Test
Limits
1
V
10
V
1
V
lOV
0.999966
to
1.000034
9.99977
to
10.00023
0.999936
to
1.000064
9.99947
to
10.00063
f.
Set the
3455A
HIGH RESOLUTION
to
OFF. The
34SSA
reading should
be
within
test
limits
listed
in
Table
4-9,
verifying
its
10-volt
full
scale
accuracy with
High
Resolution
off.
g.
Set the
Transfer
Standard
for
an output of
1
V
and
set
the
3455A
RANGE
to
1
V.
Set the
3455A
GUARD
to
OFF;
connect
the
34SSA
GUARD
terminal
to
the
High
INPUT
terminal.
h.
Reverse
the
34SSA
INPUT
connection
to
obtain
a
negative
1
V
reading.
Repeat
Steps
c
through
f
to
verify
the
I
V
and
10
V
full-scale
accuracy
for
negative
readings.
i.
Disconnect
the
Transfer
Standard
from
the
345SA
INPUT.
Disconnect
the
GUARD
terminal
from
the
High
INPUT
terminal
and
set
the
GUARD
to
ON.
j.
Using
short pieces
of
number
20
AWG
(or thinner)
insulated
solid
copper
wire,
connect
the
Transfer Stan-
dard
and
DC
Null Voltmeter
to the
Reference
Divider as
shown
in
Figure
44.
k.
Turn
off the
DC
Standard's output. Using
24"
(or
shorter) shielded cables
equipped
with
banana-plug
con-
nectors,
connect
the
DC
Standard
and
the
34S5A
to
the
Reference Divider
as
shown
in
Figure
44.
l.
Set the
Standard
Cell
Voltage
controls
on
the
Reference
Divider
to
correspond
to the calibrated
standard-cell
setting
on
the
Transfer Standard.
Set
the
Transfer
Standard
to
output
the calibrated standard-cell
voltage.
m. Zero
the
DC
Null
Voltmeter
on
its
3
microvolt
range
and
then
set
it
to
the
300
microvolt range.
n.
Set the
Reference
Divider's
Input Voltage switch
to
10(X)
V
and
center
its
course
and
fine
adjustment con-
trols.
Set the
Reference
Divider's
Output
Voltage
switch
to
1000 V.
o.
Set the
34SSA
controls
as follows:
4-10
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