HP 3457A - 5-19. CALIBRATION PROCEDURES - FRONT PANEL INPUTS; 5-21. DC Volts Offset Calibration - Front Terminals

3457A
Calibration
f. Lay the plug-in support assembly over the front panel to gain access to the AC convertor frequency
response adjustment (Gain/Flatness A3C332).
g. Reconnect power to the instrument and turn it ON.
h. Run the AC Auto-Cal routine. (Press the AUTO CAL configuration key, enter the number 2 and press the ENT
key ).
i. Enable Diagnostic Routine number 8. (Press the Blue SHIFT key then the AUTO ZERO / D configuration
key. Use the | scroll key to display DIAGNOSTIC. Enter the number 8 and press the ENT key).
j. Use an insulated adjustment tool to adjust A3-C332 (Gain/Flatness adj) until the display reads
PASSED 0.
k,
Exit
the
Diagnostic
Routine.
(Press
and
hold
the
> /
RESET
display
key
until
a
tone
is
heard
).
1.
Turn the
instrument
OFF
and
remove
the
power
cord.
m, Replace
the
plug-in
support assembly,
top
cover and
terminal
or
terminal
block
assembly.
n, Reconnect power and turn the instrument ON.
5-19. CALIBRATION PROCEDURES - FRONT PANEL INPUTS
5-20. Calibration of the 3457A from the front input terminals consists of calibrating the offset and gain of
each range for the DCV, 2-Wire Ohms, 4-Wire Ohms and DCI Functions and gain of each range for the
ACV and ACI Functions. The FREQ Function is calibrated at one frequency.
The Preliminary Calibration Procedures should be completed before attempting
the following procedures.
5-21. DC Volts Offset Calibration - Front Terminals
5-22. Equipment Required. A low thermal short (copper wire) is required for this procedure.
a. Select the DC Voltage Function. (Press the DCV function key ).
b. Connect a short between the front panel HI and LO input terminals.
c.
Use
the
following
procedure
to
calibrate
the
front
terminal
offset
on
the
30
mV,
300
mV,
3
V,
30
V
and
300
V
ranges
beginning
with
the
300
V
range
and
ending
on
the
30
mV
range.
1,
Set
the
3457A
to
the
appropriate
voltage
range.
(Use
the
{
or
a}
scroll
key
to
select
the
proper
voltage
range).
2.
Access
the
Calibration
Command.
(Press
the
Blue
SHIFT
key,
then
the
OFFSET
COMP
/
C
configura-
tion
key).
The
display will
show
CAL.
3.
Enter
the
value
of
the
input;
in
this
case
0.
(NOTE:
If
the
security
feature
has
not
been
disabled,
(set
to
0)
it
will
be
necessary
to
enter
the input value,
the delimiter
(
,
)
and the
security
code).
5-5