Keithley SourceMeter 3A 2420, Service Manual

Page: 42 / 136

2-12 Calibration
16. Press ENTER The Model 2420 will source -0
µ
A and simultaneously display the following:
DMM RDG: +00.00000
µ
A
Use
, , , ,
ENTER, or EXIT.
17. Note and record the DMM reading, and then adjust the display to agree with the DMM
reading. Once again, the maximum adjustment is within ±1% of the present range.
18. After adjusting the display to agree with the DMM reading, press ENTER to complete
calibration of the present range.
19. Press EXIT to return to normal display, and then select the 100
µ
A source range use the
EDIT and up RANGE keys. Repeat steps 2 through 18 for the 100
µ
A range.
20. After calibrating the 100
µ
A range, repeat the entire procedure for the 1mA through 1A
ranges using Table 2-4 as a guide. Be sure to select the appropriate source range with the
EDIT and up RANGE keys before calibrating each range.
21. After calibrating the 1A range, connect the 1
Ω
characterized resistor and DMM to the
Model 2420 INPUT/OUTPUT jacks, as shown in Figure 2-3.
22. Select the DMM DC volts function.
23. Repeat steps 2 through 18 for the 3A range using Table 2-4 as a guide. When entering
the DMM reading, use the calculated current as follows: I = V/R, where V is the DMM
voltage reading, and R is the characterized value of the 1
Ω
resistor.
Digital Multimeter
2420 3A SourceMeter
250V
PEAK
5V
PEAK
HI
LO
OUTPUT
75V
PEAK
75V
PEAK
EDIT
TOGGLE
POWER
RANGE
INPUT/
OUTPUT
4- WIRE
SENSE
DISPLAY
ON/OFF
TERMINALS
FRONT/
REAR
AUTO
RANGE

EXIT ENTER CONFIG MENU
SWEEP TRIG REL LOCAL FILTER LIMIT
DIGITS SPEED
V
Ω
MEAS
I
FCTN
V I
SOURCE
2 3 0 1
6 7 8 9
4
+/-
5
STORE RECALL
EDIT
Model 2420
Input HI
Input LO
1
Ω
Resistor
Figure 2-3
3A range current
calibration test
connections