Aborting Calibration; Current Calculations; Calibration Procedure; Preparing For Calibration - Keithley 6485 Instruction Manual

16-6 Calibration

Aborting calibration

You can abort the calibration procedure at any time by pressing the EXIT key.

Current calculations

When calibrating the 2nA-2µA current ranges, you must calculate the actual current val-
ues from the applied calibrator voltages and the characterized Model 5156 Calibration
Standard resistor values. Calibration currents are calculated as follows:
Where: I = required calibration current
For example, assume you are calibrating the 20nA range using a 2V calibrator voltage
with an actual 100.5MΩ standard resistor value. The actual calibration current is:
2V/100.5MΩ = 19.9005nA.

Calibration procedure

The calibration procedure should be performed in the following order:
•
•
•
•
•

Preparing for calibration

1.
2.
3.
4.
I = V/R
V = calibrator voltage
R = actual standard resistor value
Preparing for calibration
Offset voltage calibration
Current calibration
Entering calibration dates and saving calibration
Locking out calibration
Turn on the Model 6485 and the calibrator, and allow them to warm up for at least
one hour before performing calibration.
Press MENU, select CAL, then press ENTER. The instrument will display the fol-
lowing:
CAL: VOFFSET
Use the up or down RANGE key to display the following:
CAL: UNLOCK
Press ENTER. The instrument will prompt for the calibration code:
CODE? 000000
Model 6485 Instruction Manual