Keithley 6430 Instruction Manual page 443

1pA-100nA range accuracy
1. With the power off, connect the digital multimeter and calibration standard to the main-
frame and PreAmp as shown in Figure 18-7. (Connect the mainframe INPUT/OUTPUT
HI and LO jacks to DMM INPUT HI and LO respectively. Connect the PreAmp IN/
OUT HIGH jack directly to the Model 5156 OUTPUT jack, and connect the BNC
shorting cap to the 100GΩ resistance jack. Also be sure to remove the link between
the Model 5156 SHIELD and CHASSIS jacks.)
2. Select the multimeter DC current function.
3. Set the Model 6430 to both source and measure current by pressing the SOURCE I and
MEAS I keys, and make sure the source output is turned on.
4. Verify measure current accuracy for the currents listed in Table 18-13. For each
measurement:
• Connect the BNC shorting cap to the correct Model 5156 resistance jack.
• Select the correct source range.
• Calculate the current from the DMM reading and actual standard resistance:
I = V/R.
• Set the Model 6430 source output to the calculated current.
• Verify that the Model 6430 current reading is within the limits given in the table.
NOTE
It may not be possible to set the current source to the specified value. Use the closest
possible setting, and modify reading limits accordingly.
5. Repeat the procedure for negative currents with the same magnitudes as those listed in
Table 18-13.
Table 18-13
Remote PreAmp 1pA-100nA range measurement accuracy limits
Model 6430 Standard
range resistor
1pA 100GΩ
10pA 100GΩ
100pA 10GΩ
1nA 1GΩ
10nA 1GΩ
100nA 100MΩ
1
Nominal values. Use characterized values in current calculations.
2
Calculated from DMM reading and nominal resistance values. Use closest value, and modify reading limits
accordingly. Limits shown include Model 5156 characterization uncertainty.
1
Source current
1.000000pA
10.00000pA
100.000pA
1.00000nA
10.0000nA
100.000nA
Performance Verification
Model 6430 current reading
limits (1 year, 18°-28°C)
0.98300 to 1.01700pA
9.9430 to 10.0570pA
99.820 to 100.180pA
0.99930 to 1.00070nA
9.9930 to 10.0070nA
99.930 to 100.070nA
18-25
2