Keithley 2000-SCAN-20, Instruction Manual

Page: 60 / 81

Service Information 4-9
21. Repeat steps 14 through 20 to measure isolation resistance between channel 1 HI and
each HI input of channels 3 through 20. Be sure the electrometer is connected to the HI
inputs of the two channels being tested and channel 1 is closed.
22. Repeat steps 14 through 21 for the LO inputs of channels 1 through 20. Be sure the
electrometer is connected to the LO inputs of the two channels being tested and channel
1 is closed.
23. Turn off the multimeter power.
24. With the electrometer voltage source off, connect the Model 6517A Electrometer to
channel 1 HI and chassis ground as shown in
Figure 4-5 .
Figure 4-5
Connections for HI and LO input-to-chassis ground isolation tests
25. Turn on the Model 2000-20 Multimeter power.
26. Program the multimeter to close channel 1.
27. On the electrometer, source 60V.
28. After allowing the reading on the electrometer to settle, verify that it is >100M
Ω
(10
8 Ω
).
29. Turn off the electrometer voltage.
30. Turn off the multimeter power.
31. Repeat steps 24 through 30 for channels 2 through 20. One electrometer lead should be
connected to the HI input of the channel being testing, and the other lead should be con-
nected to chassis ground.
32. Repeat steps 24 through 31 for the LO inputs of channels 1 through 20. One electrometer
lead should be connected to the LO input of the channel being tested, and the other lead
should be connected to chassis ground. Also, channel 1 should be closed.
HI
LO
Channel 1
HI
LO
Channel 2-9
Channel 10
HI
LO
Channel 11
HI
LO
Channel 12-19
Channel 20
HI
LO OUT A
OUT B
HI
2-Pole 4-Pole
HI
Model
6517A
V-Source HI
(Red)
Banana to
Banana
Cable
Com
(Ground Link
Removed)
V-Source LO
Model 6171
Triax Adapter
Model 7025
Unterminated
Triax Cable
Source V and
Measure V/I
LO
Unterminated to
Banana Cable
Chassis Ground
Model 2000-SCAN-20