88
34405A User’s and Service Guide
4
Performance Tests and Calibration
Adjustments
You will need a test input cable and connectors set, and a Shorting Plug
to adjust the instrument (see
“Input Connections”
on page 67).
Zero Adjustment
Each time you perform a zero adjustment, the instrument stores a new set
of offset correction constants for measurement functions and ranges. The
instrument will sequence through all required functions and ranges
automatically and store new zero offset calibration constants.
Zero Adjustment Procedure
Be sure to allow the instrument to warm up and stabilize for 2 hours
before performing the adjustments.
1
Follow the steps outlined below. Review
“Test Considerations”
on
page 67 before beginning this test.
2
After unsecuring the instrument, the instrument goes into the
Adjustment Mode (as indicated by the
CAL
annunciator) with the
secondary display showing
Short
. Connect the Shorting Plug (see
page 68
) between the HI and LO front panel input terminals. Leave the
current inputs open.
N O T E
After each adjustment finishes successfully, the primary display briefly shows
PASS
. If the
calibration fails, the multimeter beeps, the primary display shows
FAil
and an error number
is shown in the secondary display. Calibration error messages are described on
page 103
. In
the event of a calibration failure, correct the problem and repeat the procedure.
C A U T I O N
Never turn off the instrument during Zero Adjustment. This may cause ALL calibration
memory to be lost.
N O T E
To minimize thermal effects wait at least 1 minute after connecting the Shorting Plug before
executing the zero adjustment.
Downloaded from
www.Manualslib.com
manuals search engine
