Service manual

PN 4237242C
4.24-3
SERVICE AND REPAIR PROCEDURES
APERTURE, BATH AND APERTURE ELECTRODE MODULE
4
2. Install the aperture block (Figure 4.24-1):
a. Verify that there are small O-rings at the top and bottom of the block.
b. Verify that the O-rings are in good condition. If they are too flat or beginning to
deteriorate, replace them.
c. Verify that the area around the aperture bath is dry.
d. Tighten the fitting below the aperture block. It only needs to be snug, or tight
enough to ensure that the O-ring seals are compressed.
3. Install the aperture bath (Figure 4.24-1):
a. Verify that the large aperture O-ring seal is seated in its groove in the bath. This seal
will be pressure-fit against the front of the aperture block.
b. Position the Aperture Electrode module against the rear pressure plate.
c. Slide the bath in place until it can be fit onto the aperture block.
d. Set the metal insert (front pressure plate) in place and tighten the thumbscrew
against it. This should be a snug fit, only finger-tight.
4. Connect the bath electrode (external electrode connector) to the connector on the
Aperture Electrode module (Figure 4.24-1).
Verification
1. Turn ON the instrument’s power.
2. Perform a startup. Observe the bath and aperture area closely for any fluid leaks or air
leaks in the sweep flow or internal electrode path.
3. Replace the inner shield door and close the lower chassis.
4. If there are no visible problems, perform an SVP (Heading 5.1).