Technical data

Calibration Procedures 3
34980A Service Guide 49
Calibration Process
The following general procedure is the recommended method to complete a
full instrument calibration.
1 Read “DMM Test Considerations" on page 53 and “Plug- in Module Test
Considerations" on page 65.
2 Perform the verification tests to characterize the instrument (incoming
data).
3 Unsecure the instrument for calibration (“Calibration Security" on
page 47).
4 Perform the DMM adjustment procedures (“Internal DMM
Adjustments" on page 60).
5 Perform the DAC adjustment procedures if either the 34951A (“34951A
4- Ch Isolated DAC Module" on page 66) or 34952A (“34952A
Multifunction Module" on page 71) is installed.
6 Secure the instrument against calibration.
7 Note the new security code and calibration count in the instrument’s
maintenance records.
Aborting a Calibration in Progress
Sometimes it may be necessary to abort a calibration after the procedure
has already been initiated. You can abort a calibration at any time on any
module by turning off the power. You can abort a calibration on the
internal DMM or the 34951A 4- Ch Isolated DAC by issuing a remote
interface device clear message. You can abort a calibration on the 34952A
Multifunction Module by sending the
CALibration:ABORt command.
NOTE
The 34951A 4-Ch Isolated DAC is intended to be adjusted frequently to
compensate for changes in the module’s environment. These
adjustments can be made either volatile or non-volatile. See page 66 for
details.
CAUTION
If you abort a calibration in progress when the instrument is attempting
to write new calibration constants to EEPROM, you may lose all
calibration constants for the function. Typically, upon re-applying
power, the instrument will report error 705 Cal:Aborted. You may also
generate errors 740 through 746. If this occurs, you should not use the
instrument until a complete re-adjustment has been performed. For a list
of calibration error numbers, see page 86.