Keithley 7035, Инструкция по эксплуатации

Страница: 42 / 74

Service Information
5-3
Channel resistance tests
Perform the following steps to verify that each contact of
every relay is closing properly and that the resistance is
within specification.
1. Turn off the Model 7001/7002 mainframe if it is on.
2. Turn on the Model 2000 and allow it to warm up for one
hour before making measurements.
3. Connect all input terminals of bank A together to form
one common terminal, as shown in Figure 5-1.
4. Set the Model 2000 to the 100
Ω
range and connect the
four test leads to the INPUT and INPUT
Ω
4 WIRE
jacks.
5. Short the four test leads together and zero the Model
2000. Leave zero enabled for the entire test.
6. Connect INPUT HI and INPUT
Ω
4 WIRE HI of the
Model 2000 to the common terminal (jumper on bank A
inputs). It is recommended that the physical connections
be made at inputs 1 and 4 of bank A, as shown in
Figure 5-1.
7. Connect INPUT LO and INPUT
Ω
4 WIRE LO to the HI
(H) terminal of bank A.
8. Install the Model 7035 in slot 1 (CARD 1) of the Model
7001/7002.
9. Turn on the Model 7001/7002 and program it to close
channel 1!1 (bank A, input 1). Verify that the resistance
of this path is <1
Ω
.
10. Open channel 1!1 and close channel 1!2 (bank A,
input 2). Verify that the resistance of this path is <1
Ω
.
11. Using the basic procedure in steps 9 and 10, check the
resistance of bank A HI (H) terminal paths for inputs 3
and 4 (channels 1!3 and 1!4).
12. Turn off the Model 7001/7002 and move the INPUT LO
and INPUT
Ω
4 WIRE LO test leads to the LO (L) ter-
minal of bank A.
13. Repeat steps 9 and 10 to check the LO (L) terminal paths
of bank A (channels 1!1 through 1!4).
14. Repeat the basic procedure in steps 1 through 13 for
bank B through I (channels 1!5 through 1!36).
Figure 5-1
Path resistance test connections
HI
LO
POWER
Note: Connections are set
up to test Bank A HI.
Customer-supplied
jumpers
Bank
Outputs
Bank Inputs
Model 7035
Input
Ω
4 Wire
Input HI
Input LO
Input
Ω
4 Wire LO
Model 2000
(Measure 4-Wire Ohms)
H L H L H L H L
A
1 3 4 2
B
C
D
E
F
G
H
I
H
L
H
L
H
L
H
L
H
L
H
L
H
L
H
L
H
L