Calibration
2-12
Step 14: Lock out calibration
To lock out further calibration, send the following command
after completing the calibration procedure:
:CAL:PROT:LOCK
2.9
AC self-calibration
The AC self-calibration procedure requires no external
equipment and can be performed at any time by the user. As
the name implies, this calibration procedure assures the ac-
curacy of ACI and ACV measurements.
In general, AC calibration should be performed one-hour af-
ter power-on or at least once every 24 hours for optimum AC
measurement accuracy.
NOTE
The AC calibration constants generated by
this procedure are not permanently stored.
Thus, AC calibration constants are in ef-
fect only until the power is turned off. In
order to permanently store AC calibration
constants, you must perform the compre-
hensive or low-level calibration procedure
and then choose to save calibration con-
stants at the end of that procedure. See
paragraph 2.8 or 2.10 for details.
2.9.1 Front panel AC calibration
Procedure:
1. Disconnect all test leads or cables from the INPUT and
SENSE jacks.
2. Press MENU. The instrument will display the follow-
ing:
MAIN MENU
SAVESETUP
GPIB
CALIBRATION
3. Select CALIBRATION, then press ENTER. The Model
2001 will display the following:
PERFORM CALIBRATION
COMPREHENSIVE
AC-ONLY-CAL
4. Select AC-ONLY-CAL, then press ENTER. The instru-
ment will display the following message:
AC CALIBRATION PHASE
Open-circuit inputs, press ENTER
5. Press ENTER to begin AC calibration, which will take
about six minutes to complete. During AC calibration,
the instrument will display the following:
Calibrating AC: Please wait
6. Once the process has been successfully completed, the
message below will be displayed, and you can press EN-
TER or EXIT to return to normal display:
AC CAL COMPLETE
Press ENTER or EXIT to continue.
2.9.2 IEEE-488 bus AC self-calibration
Procedure:
1. Disconnect all test leads and cables from the INPUT and
SENSE jacks.
2. Send the following command over the bus:
:CAL:UNPR:ACC
3. Wait until calibration has been completed before send-
ing any further commands.
4. Check for calibration errors by using the :SYST:ERR?
query.
2.10 Low-level calibration
Low-level calibration is normally performed only at the fac-
tory when the instrument is manufactured and is not usually
required in the field. The following paragraphs give detailed
procedures for performing low-level calibration should it
ever become necessary in the field.
NOTE
Low-level calibration is required in the
field only if the Model 2001 has been re-
paired, or if the other calibration proce-
dures cannot bring the instrument within
stated specifications. The low-level cali-
bration procedure includes the compre-
hensive calibration steps discussed in
paragraph 2.8. Comprehensive calibration
steps must be performed before perform-
ing the low-level calibration steps.