Keithley 2500 - Page 23

1-8 Performance Verification Model 2500 Service Manual
7. Verify that the Model 2500 current reading is within the limits for the 2nA range
shown in Table 1-2.
8. Repeat steps 4 through 7 for the 20nA through 20mA ranges. (Use the calibrator
active amps mode for the 20mA range.)
9. Repeat steps 4 through 8 for negative input currents of the same magnitude.
10. After verifying all ranges on channel 1, repeat the entire procedure for channel 2.
Connect the calibrator to the INPUT CHANNEL 2 jack, and select channel 2 by
pressing MSR2. (See Figure 1-2 for connections.)
Table 1-2
Current measurement verification limits
Model 2500 range Calibrator current
Reading limits*
1 year, 65°F to 82°F (18˚C to 28˚C)
2nA 1.90000nA 1.87900 to 1.92100nA
20nA 19.0000nA 18.9220 to 19.0780nA
200nA 190.000nA 189.230 to 190.770nA
2 µ A 1.90000 µ A 1.89600 to 1.90400 µ A
20 µ A 19.0000 µ A 18.9610 to 19.0390 µ A
200 µ A 190.000 µ A 189.790 to 190.210 µ A
2mA 1.90000mA 1.89610 to 1.90390mA
20mA 19.0000mA 18.9790 to 19.0210mA
*Limits do not include calibrator uncertainty.