Restoring Factory Defaults - Keithley 6430 Instruction Manual

18-6 Performance Verification
Resistance limits calculation
When verifying the resistance measurement accuracy, it will most likely be necessary to
recalculate resistance limits based on the actual calibrator resistance values. You can calculate
resistance reading limits in the same manner described above, but be sure to use the actual
calibrator resistance values and the Model 6430 normal accuracy specifications for your
calculations.
As an example, assume you are testing the 20kΩ range, and that the actual value of the nom-
inal 19kΩ calibrator resistor is 19.01kΩ. Using the Model 6430 20kΩ range one-year normal
accuracy specifications of ±(0.063% of reading + 3Ω), the recalculated reading limits are:
Reading limits = 19.01kΩ ± [(19.01kΩ × 0.063%) + 3Ω]
Reading limits = 19.01kΩ ±15Ω
Reading limits = 18.9950kΩ to 19.0250kΩ
Limits calculation with test equipment uncertainty
Reading limits given in this section for the 1pA-100nA and 2GΩ-200GΩ ranges include the
characterization accuracy of the Model 5156 Electrometer Calibration Standard. Reading limits
for these ranges are calculated as indicated above except that they also take into account Model
5156 uncertainty. For example, using the 1GΩ Model 5156 resistor to test the Model 6430
2GΩ range, we have:
Model 6430 normal accuracy specifications: ±(0.085% + 100kΩ)
Model 5156 1GΩ characterization accuracy: 300ppm (0.03%)
Assuming an actual Model 5156 characterized value of 1.02GΩ, we have:
Reading limits = 1.02GΩ ± [(1.02GΩ × (0.085% + 0.03%)) + 100kΩ]
Reading limits = 1.02GΩ ±1.273MΩ
Reading limits = 1.01873GΩ to 1.02127GΩ
Performing the verification test procedures

Restoring factory defaults

Before performing the verification procedures, restore the instrument to its factory front
panel (bench) defaults as follows:
1.
2.
Press the MENU key. The instrument will display the following prompt:
MAIN MENU
SAVESETUP COMMUNICATION CAL
Select SAVESETUP, and then press ENTER. The unit then displays:
SAVESETUP MENU
GLOBAL SOURCE-MEMORY