Model 6487 Reference Manual
Performance Verification
15-7
Offset voltage calibration
Before performing the current performance verification procedure, perform offset voltage
calibration as outlined below.
1.
Press the MENU key, select CAL, then press ENTER.
2.
The unit will display the following:
CAL: VOFFSET
3.
Press ENTER. The instrument will prompt as follows:
INPUT CAP
4.
Connect the triax shielding cap to the INPUT jack.
5.
Press ENTER to complete offset voltage calibration.
6.
Press EXIT to return to normal display.
Current measurement accuracy
Follow the steps below to verify that Model 6487 current measurement accuracy is within
specified limits. The test involves applying accurate DC currents and then verifying that
the Model 6487 current readings are within required limits.
20µA-20mA range accuracy
1.
With the power off, connect the current calibrator to the Model 6487 INPUT jack
(
). Use the appropriate coax cable, triax-to BNC adapter, and BNC-to-
dual banana plug adapter where shown.
2.
Turn on the Model 6487 and calibrator. Allow them to warm up for one hour.
3.
Set the Model 6487 to the 20
μ
A range using the up or down RANGE key.
4.
With zero check enabled, zero correct the Model 6487 and then disable zero check.
5.
Set the calibrator current to 0.0000
μ
A and make sure the output is turned on.
6.
Enable the Model 6487 REL mode. Leave REL enabled for the remainder of the
test.
7.
Verify current measurement accuracy for each of the currents listed in
For each test point:
•
Select the correct Model 6487 measurement range.
•
Set the calibrator current to the indicated value.
•
Verify that the Model 6487 current reading is within the limits given in the
table.
8.
Repeat the procedure for negative source currents with the same magnitudes as
those listed in
.
