Keithley SourceMeter 2425, Service Manual, Page: 130 / 141

Model 2425 Service Manual Calibration Programs C-3
General program instructions
1. With the power off, connect the Model 2425 and the digital multimeter to the
IEEE-488 interface of the computer. Be sure to use shielded IEEE-488 cables for
bus connections.
2. Turn on the computer, the Model 2425, and the digital multimeter. Allow the
Model 2425 and the multimeter to warm up for at least one hour before performing
calibration.
3. Make sure the Model 2425 is set for a primary address of 24. (Use the front panel
MENU/GPIB selection to check or change the address.)
4. Ensure the digital multimeter primary address is set to its factory default setting
(22).
5. Ensure that the computer bus driver software (CECHP.EXE) is properly initialized.
6. Enter the QBasic editor, and type in the program below.
NOTE Be sure to change the OneOhm parameter to the characterized value of 1
Ω
resistor. (See Section 2 for details.)
7. Check thoroughly for errors, then save it using a convenient filename.
8. Run the program, and follow the prompts on the screen to perform calibration. For
test connections, refer to the following figures in Section 2:
• DMM volts connections: Figure 2-1.
• 10
μ
A to 1A range current connections: Figure 2-2.
• 1
Ω
resistor and DMM connections for 3A range: Figure 2-3.