Keithley 7035, Instruction Manual

Page: 47 / 74

Service Information
5-8
Bank and channel-to-channel isolation tests
Bank isolation tests check the leakage resistance between
adjacent banks. Channel-to-channel isolation tests check the
leakage resistance between a bank output connection and a
bank input connection with an adjacent bank input relay
closed. In general, the tests are performed by applying a volt-
age (60V) across the leakage resistance and then measuring
the current. The isolation resistance is then calculated as
R = V/I. In the following procedure, the Model 6517A func-
tions as both a voltage source and an ammeter. In the R func-
tion, the Model 6517A internally calculates the resistance
from the known voltage and current levels and displays the
resistive value.
Perform the following steps to check bank and channel-to-
channel isolation:
1. Turn off the Model 7001/7002 mainframe if it is on, and
remove any jumpers or test leads connected to the mul-
tiplexer.
2. Turn on the Model 6517A and allow the unit to warm up
for two hours before testing.
3. Connect the electrometer to the Model 7035 as shown in
Figure 5-4.
4. Install the Model 7035 in slot 1 (CARD 1) and turn on
the mainframe.
WARNING
The following steps use a 60V source. Be
sure to remove power from the circuit
before making connection changes.
5. Place the Model 6517A in the R measurement function.
Figure 5-4
Bank isolation test connections
Bank
Outputs
Bank Inputs
Model 7035
WARNING:
NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.
WARNING:
NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.
CAUTION:
FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.
CAUTION: FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.
!
1
15V
!
90-110V
105-125V
180-220V
210-250V
Banana to
Banana Cable
Ground Link
Removed
Source V and
Measure V/I
A
B
C
1 3 4 2
HI
Model 6517A
(Red)
Unterminated
Banana Cables
Note: Setup shown is configured
to test isolation between
Bank A and Bank B.
D
E
F
G
H
I
Model 7025
Unterminated
Triax Cable
H L H L H L H L
H
L
H
L
H
L
H
L
H
L
H
L
H
L
H
L
H
L