Service manual

PN 4237242C
4.24-2
SERVICE AND REPAIR PROCEDURES
APERTURE, BATH AND APERTURE ELECTRODE MODULE
7. Remove the thumbscrew at the front of the aperture bath assembly (Figure 4.24-1). The
bath, aperture, and rear module are pressure-fit and this thumbscrew provides the pressure.
8. Remove the aperture bath. To get enough room at the front of the bath to clear the
aperture block, you may have to remove the metal insert (Figure 4.24-1) that the
thumbscrew presses against.
9. If you are replacing the bath only, go to Installation, step 2.
10. If you are replacing the RBC aperture block, remove the sweep-flow tubing. Loosen the
fitting that pushes up against the aperture from underneath. This allows the aperture
block to be easily pulled out of the Aperture Electrode module.
11. Remove the aperture blocks from the Aperture Electrode module (Figure 4.24-1). The
Aperture Electrode module is not attached and can be moved to a convenient working position.
12. If you are not going to replace the Aperture Electrode module, go to Installation, step 3
of this section.
13. Open up the lower chassis and raise the upper chassis.
14. Remove the two covers that shield the Sensor Preamp Adapter card and the electrode
cables. See the replacement procedures (Heading 4.16) for details on removing these
covers.
15. Slide the Sensor Preamp Adapter card up until you can remove the electrode cable for the
Aperture Electrode module you are replacing.
16. Remove the Aperture Electrode module by pulling the cable through the Diluter Panel
(Figure 4.24-1).
Installation
1. Install the new Aperture Electrode module into the unit:
a. Feed the coaxial cable through the hole in the Diluter Panel (Figure 4.24-1).
b. Slide the Sensor Preamp Adapter card up until you can connect the coaxial cable to
its proper connector. The lower connector is for the WBC module and the upper
connector is for the RBC module.
c. Replace the shield covers for the Sensor Preamp Adapter card and the electrode cables.
d. Close the upper chassis.