Performance Tests and Calibration 4
34405A User’s and Service Guide 93
Adjustments
You will need a test input cable and connectors set, and a 
Shorting Plug to adjust the instrument (see “Input 
Connections” on page 72).
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 71 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 73) between the HI 
NOTE
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 110. In the event 
of a calibration failure, correct the problem and repeat the procedure.
CAUTION
Never turn off the instrument during Zero Adjustment. This may cause 
ALL calibration memory to be lost.
34405A users guide.book  Page 93  Saturday, September 2, 2006  3:38 PM