Stereo Scan 440 - DCU

5-6 Chapter 5 Maintenance
Cleaning the Gun Assembly
1. Vent the column and chamber to air.
Open the gun.
3. Loosen the three filament assembly clamp screws (1) and remove the
filament assembly (2).
4.
Lift out the anode (3). Take care, as the anode is a very good fit on the
top of the alignment coils (4).
"
~, Close the gun while the components are cleaned. Take the filament
assembly and anode to a clean area for cleaning.
6.
Using the flat metal key unscrew the height adjustment ring and remove
the filament carrier.
Loosen the four screws (see Figure 5.2) holding the filament into the
carrier and remove the filament.
8. Clean the grid and anode.
9. Replace the anode on top of the alignment coil making sure that it is
correctly seated into its location boss. The anode should sit level on the
alignment coil and be free to rotate, but not loose.
10. If necessary change the filament, centre it in the grid and replace the
assembly in the gun (as described in Section 2.2.4 Changing the
Filament).
11
Pump down the column and chamber and run up the gun, not forgetting
to check the filament saturation and gun alignment, as these may have
changed with the new filament.
Stereoscan 440 Operator Manual