Preliminary Calibration Procedures - HP 3457A Service Manual

Calibration
c. The display will show CALNUM? and the current calibration number.
d. Press any key t o return the instrument to normal operation.
5-1 3. PRELIMINARY CALIBRATION PROCEDURES
5-14. The following steps should be performed prior to calibration of the 3457A:
a. Select the calibration area. The 3457A may be calibrated in a "bench environment or in a system
cabinet. For greatest accuracy, select an area where the temperature is between 18OC and 28OC and
stable within
f
5
O
C.
b. Connect the 3457A t o an appropriate power source and turn the instrument ON. The 3457A can
operate on line voltages from 100 Vac t o 240 Vac, 50 Hz or 60 Hz. Refer t o Section
11,
Line Voltage
Selection, for proper rear panel switch settings and fuse selection.
c. Remove all external input signals from the front and rear/scanner input terminals.
d. Run the instrument Self Test.
(Press the Blue S H I F T key then the
+
/
T E S T key). The display will show
TESTINQ while the test routine is running.
1. If the display shows
SELF TEST OK
after the test has completed, continue with step
"
e
".
2. If the display shows TEST FAILED, check the ERROR message.
(Press the Blue S H I F T key then the
-
/
ERROR key).
*
If the Error Message reads OUT OF CALIBRATION, continue with step
"
e
".
( I t is probable
that performing the Calibration Procedures will eliminate this error).
If the Error Message reads
HARDWARE ERR,
check the
AUXERR?
(Auxiliary Error) mes-
sage for additional information.
(Press the Blue S H I F T key then the NPLC
/
A configuration key. Use
the scroll key t o display
A
U X E R R . Press the ENT key).
An AUXERR?
message of 16 indicates the Input Amplifier Offset is beyond tolerance.
Perform the Input Amplifier Offset adjustment (Paragraph 5-15) and repeat steps
"
d
"
through
"
h
"
of this procedure.
An
AUXERR?
message of 256 indicates the AC attenuator frequency compensation is
beyond tolerance. Perform the AC Convertor Frequency Response adjustment (Paragraph
5-17) and repeat steps
"
d
"
through
"
h
"
of this procedure.
0
An AUXERR?
message, other than 16 or 256 indicates a component failure. Refer t o
Section VIII for repair procedures.
e. Allow the instrument t o warm-up for a period of one hour.
f. Run the
AUTO CAL
(Autocalibration) routine.
(Press the AUTO C A L configuration keg, t o display the
ACAL command, enter the number 1 and press the ENT key).
g. Record the Calibration Number if desired. (Refer t o paragraph 5-10).
h. Proceed t o the calibration procedures beginning at paragraph 5-19.