Section 7
7-16
25. Set the current to 0 mA.
26. Repeat Steps 16 to 25.
7.2.4.3.2.Output Impedance Calibration
1. Remove the 10 resistors and the links from the Rs and Rx front
panel terminals.
2. Short Rs C
1
to Rs C
2
.
3. Connect a 1 k, 0.1% resistor across Rx C
1
and Rx C
2
.
4. Using a 10 M input impedance DMM, monitor the voltage at Rx
C
2
with respect to Rx C
1
(use the 2 V range on the DMM).
5. Note the voltage at Rx C
2
with respect to Rx C
1
.
6. Set the current to 0.3 mA.
7. Note the voltage swing at Rx C
2
with respect to Rx C
1
.
8. Set the current to 0 mA.
9. Remove the 1 k resistor and connect a 100 k, 0.1% ULT resistor
across Rx C
1
and Rx C
2
.
10. Using a 10 M input impedance DMM, monitor the voltage at Rx
C
2
with respect to Rx C
1
(use the 200 V range on the DMM).
11. Note the voltage at Rx C
2
with respect to Rx C
1
.
12. Set the current to 0.3 mA.
13. Note the voltage swing at Rx C
2
with respect to Rx C
1
.
14. If necessary, adjust potentiometer R213 on the Primary Current
Drive PCB to obtain a voltage swing of within 0.1 % of 99x the
voltage swing noted in Step 7.
To Next Page
Loading...