Remote Preamp Resistance Measurement Accuracy - Keithley 6430 Instruction Manual

18-26 Performance Verification

Remote PreAmp resistance measurement accuracy

Use the following steps to verify that Model 6430 Remote PreAmp resistance measurement
accuracy is within specified limits. This procedure involves applying accurate resistances from
a resistance calibrator or standard resistor and then verifying that Model 6430 resistance mea-
surements are within required limits.
NOTE
CAUTION
20Ω-200MΩ range accuracy
1.
2.
3.
Before making resistance measurements, put the Model 6430 in the AUTO SOURCE
mode (press CONFIG, then Ω , select SOURCE, select AUTO, then press ENTER).
Before testing the 20Ω and 200Ω ohms ranges, make sure your resistance
calibrator can safely handle the default test currents for those ranges
(100mA and 10mA for the 20Ω and 200Ω ranges respectively). If not, use
the Model 6430 MANUAL ohms mode, and set the test current to the max-
imum safe calibrator current. Note that Model 6430 measurement accu-
racy is reduced and reading limits should be recalculated using the
additional uncertainty when using MANUAL ohms. See the specifications
in Appendix A for details.
With the power off, connect the Remote PreAmp IN/OUT HIGH and SENSE jacks to
the resistance calibrator as shown in Figure 18-8. (Connect PreAmp IN/OUT HIGH to
calibrator OUTPUT; PreAmp SENSE to calibrator SENSE using the adapters and
cables shown.)
Select the resistance calibrator external sense mode.
Press MEAS Ω to select the ohms measurement function, and make sure the source out-
put is turned on.