Replace The Electrode Assembly; Replacing The Electronics And Magnet Housing; Clean The Internal Components - Edwards AIM-S-NW25 Instruction Manual

5.3

Replace the Electrode Assembly

Refer to Figure 4 in the following procedure.
1. Remove the AIM Gauge from the vacuum system as described in
2. Remove the body tube from the AIM Gauge as described in Step 1 of
3. Fit the flat spanner supplied in the electrode assembly kit (refer to
collar (2), then turn the collar anticlockwise to unscrew the collar from the body tube (5) and remove the anode
assembly (3) and the 'O' ring (4).
4. Use circlip pliers to remove the circlip (8) from the vacuum flange end of the body tube (5), then remove the
cathode tube (7) and the cathode plate (6).
5. Fit the new cathode plate (6) and cathode tube (7) into the body tube and secure with the circlip (8).
6. Fit the new 'O' ring (4) and anode assembly (3) into the body tube (5); ensure that the orientation of the anode
assembly is correct.
7. Refit the collar (2) to the body tube. Locate the flat spanner on the two lugs on the collar and turn the collar
clockwise until it is fully secured in the body tube.
8. Refit the body tube (5) to the magnet housing (1) as described in Steps 2 and 3 of
Gauge to the vacuum system as described in
5.4

Replacing the Electronics and Magnet Housing

The magnet housing and end-cap contain the AIM Gauge control electronics. Replace the complete unit as described
below.
1. Remove the AIM Gauge from the vacuum system as described in
2. Remove the body tube from the AIM Gauge as described in Step1 of
3. Dispose of the old magnet housing and end-cap (refer to
4. Fit the body tube to the new magnet housing and end-cap as described in Steps 2 and 3 of
the AIM Gauge to the vacuum system as described in
5.5

Clean the Internal Components

Refer to Figure 4 in the following procedure.
1. Remove the internal components from the magnet housing as described in Steps 1 to 4 of
2. The anode assembly (3) has two brackets mounted close to the disk on the anode. Use a strip of fine emery
paper to clean the gap between the disk and the brackets.
3. Use a fine screwdriver or feeler gauge and ensure that the gaps are a minimum of 0.25 mm.
4. Degrease the cathode plate (6), cathode tube (7), body tube (5) and anode assembly (3) in a suitable degreasing
agent.
5. Thoroughly soak the components in a suitable laboratory detergent.
6. Rinse the components in clean water to remove the detergent.
7. Rinse the components in methanol to remove all of the water, then thoroughly dry the components.
8. Refit the components in the magnet housing as described in Steps 5 to 8 of
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Section
Section
Section
Section 5.2.3.
Section
Section
Section 6).
Section 5.2.3.
NRA737880 Issue E
5.2.1.
5.2.2.
7) to the two lugs in the end of the
Section 5.2.2. Refit the AIM
5.2.1.
5.2.2.
Section
Section 5.3.
Section 5.3.
5.2.2. Refit
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