Keithley 2520, Service Manual, Page: 44 / 137

2-14 Calibration Model 2520 Pulsed Laser Diode Test System Service Manual
Step 4: Pulse low calibration
Follow the steps below to calibrate current source pulse low. Table 2-6 summarizes
calibration currents and test resistance values.
1. Connect DMM and 100
Ω
resistor to the Model 2520 testhead CURRENT
OUTPUT jacks, as shown in Figure 2-4 .
2. Select the DMM DC volts function, and enable auto-range.
3. Press the LASER I
L
key, press the EDIT key, then set the source to the 500mA
range using the RANGE key.
4. Press the MENU key, select CAL, then press ENTER.
5. Select EXECUTE, then press ENTER to enter the calibration menu.
6. Select PULS_LOW, then press ENTER. The unit displays:
Pulse Low CAL
Press ENTER to 15.000mA
7. Press ENTER. The unit displays:
DMM RDG: +15.000mA
Use ,
䊳
, , , ENTER or EXIT.
8. Note the DMM voltage reading, then calculate the current from the voltage and
actual resistance value: I = V/R.
9. Adjust the display to agree with the calculated current, then press ENTER. The
unit displays:
Pulse Low CAL
Press ENTER to 01.500mA
10. Press ENTER. The unit displays:
DMM RDG: +01.500mA
Use ,
䊳
, , , ENTER or EXIT.
11. Again, note the DMM voltage reading, then calculate the current from the voltage
and actual resistance value: I = V/R.
Table 2-6
Pulse low calibration values
Current source range Calibration values Calibration resistance
500mA 15mA, 1.5mA 100
Ω
5A 150mA, 15mA 10
Ω