Keithley 6485 - Page 210

16-10 Calibration Model 6485 Instruction Manual
11. Set the calibrator output voltage to –2.000000V, then calculate the calibration cur-
rent from the calibrator voltage and standard resistor value: I = V/R. Adjust the
Model 6485 display to agree with the calculated current, then press ENTER to
complete calibration of the present range.
12. Press EXIT to return to normal display.
13. Repeat steps 3 through 12 for the 20nA through 2µA ranges using Table 16-5 as a
guide. Be sure to make connections to the correct standard resistor and set the cali-
brator voltages to the correct values.
Table 16-5
2nA to 2 µ A range calibration summary
Model 6485 Range Calibrator Voltages Standard Resistors
1
Calibration Currents
2
2nA 0V
+2.000000V
-2.000000V
1GΩ
1GΩ
1GΩ
0nA
+2nA
-2nA
20nA 0V
+2.000000V
-2.000000V
100MΩ
100MΩ
100MΩ
0nA
+20nA
-20nA
200nA 0V
+20.00000V
-20.00000V
100MΩ
100MΩ
100MΩ
0nA
+200nA
-200nA
2µA0V
+200.0000V
-200.0000V
100MΩ
100MΩ
100MΩ
0µA
+2µA
-2µA
1
Nominal resistance values.
2
Nominal currents. Calculate actual currents from calibrator voltage and actual standard resistor value: I = V/R. Calibrate zero,
positive full-scale, and negative full-scale for each range.