Calibration
2-16
2.10.3 Front panel low-level calibration procedure
Procedure
Step 1: Prepare the Model 2002 for calibration
1. Turn off the power if the instrument is presently turned
on.
2. While pressing in on the recessed CAL switch, turn on
the power. (Holding in the CAL switch while turning on
the power enables low-level calibration.)
3. Allow the Model 2002 to warm up for at least four hours
before performing calibration.
4. Press the MENU key. The instrument will display the
following:
MAIN MENU
SAVESETUP GPIB CALIBRATION
5. Select CALIBRATION, then press ENTER. The Model
2002 will display the following:
PERFORM CALIBRATION
COMPREHENSIVE POINT-CALS
6. Select COMPREHENSIVE, then press ENTER.The in-
strument will display the following:
DC CALIBRATION PHASE
Step 2: DC zero calibration
1. Press ENTER. The instrument will display the follow-
ing prompt.
SHORT CIRCUIT INPUTS
2. Connect the Model 8610 low-thermal short to the instru-
ment INPUT and SENSE terminals, as shown in Figure
2-1. Wait at least three minutes before proceeding to
allow for thermal equilibrium.
NOTE
Be sure to connect the low-thermal short
properly to the HI, LO, and SENSE termi-
nals. Keep drafts away from low-thermal
connections to avoid thermal drift, which
could affect calibration accuracy.
3. Press ENTER. The instrument will then begin DC zero
calibration. While calibration is in progress, the follow-
ing will be displayed:
Performing Short Ckt Calibration
Step 3: DC volts calibration
1. When the DC zero calibration step is completed, the fol-
lowing message will be displayed:
CONNECT 2 VDC
2. Disconnect the low-thermal short, and connect the DC
calibrator to the INPUT jacks, as shown in Figure 2-2.
NOTE
Although 4-wire connections are shown,
the sense leads are connected and discon-
nected at various points in the procedure
by turning calibrator external sense on or
off as appropriate. If your calibrator does
not have provisions for turning external
sense on and off, disconnect the sense
leads when external sensing is to be turned
off, and connect the sense leads when
external sensing is to be turned on.
3. Set the calibrator output to +2.00000V, and turn external
sense off. Wait at least three minutes for thermal
equilibrium.
4. Press ENTER, and note that the Model 2002 displays
the presently selected calibration voltage:
INPUT = 2.00000000 V
(At this point, you can use the cursor and range keys to set
the calibration voltage to a value from 0.95 to 2.05V if your
calibrator cannot source 2V.)
NOTE
For best results, it is recommended that
you use the stated calibration values
throughout the procedure whenever
possible.
5. Press ENTER. The instrument will display the follow-
ing during calibration:
Performing 2 VDC Calibration
6. After completing 2VDC calibration, the instrument will
display the following:
CONNECT 20 VDC
7. Set the DC calibrator output to +20.000000V.
8. Press ENTER, and note that the instrument displays the
calibration voltage:
