HP 3455A - Page 41

Section IV
Model
3455A
Figura 4-2.
DC Accuracy Teat
Table 4-2, verifying
its
10-volt
full scale
accuracy
with
to 1000 V and center its course and fine adjustment con-
High Resolution off.
trols.
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 3455A GUARD
terminal to the
High INPUT
terminal.
h. Reverse the
3455A INPUT connection
to obtain a
negative 1 V reading.
Repeat steps
c
through
f to
verify
the 1 V and 10 V full-scale
accuracy for negative
readings.
i. Disconnect the Transfer
Standard from the 34SSA
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
4-6.
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 34SSA
to
the
Reference Divider
as
shown
in Figure
4-2.
Set the Reference Divider's Output Voltage switch
to
1000
V.
o. Set the
34SSA
controls as
follows:
FUNCTION DCV
RANGE
1
kV
HIGH RESOLUTION ON
GUARD ON
^CAUTIONj
The
dc
standard’s
output should be turned
on and the voltage
adjusted by upranging or
downranging
the standard whenever
the
standard’s output needs
to be
changed. If
a
345SA input
voltage
greater than 100 V is
needed, the following
procedure should
always
be
followed.
p.
Turn the
dc standard’s output on and by the
following
method adjust the standard for an output of
+ 1000.00
V:
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
1. Set the
dc
standard’s first
decade to
"0".
2. Uprange
the dc standard to the I(XX) V range.
3. Increase the standard’s
first decade so that 1000
V is reached by increasing the voltage
in 100
V
increments.
q.
Set the Reference Divider’s Standard
Cell
switch
to the Locked position. Adjust the dc standard’s output
4-4