e-Vision and e- LP101013.100 – 01 January 2004
MKS Instruments, Spectra Products
28
5.
Remove the two M2 x 4 pan head screws that hold the filament plate in place
and remove the filament plate assembly. Carry out this step carefully so as not to
damage the Source Cage.
6. Remove the Filament Screen (Item 5).
It is worthwhile at this stage to see if the source requires any attention, especially if
the filament(s) have broken because of an over pressure situation in your vacuum
system.
With the filaments removed you have a clear view of the source cage. The signs to
look for are powdery deposits, these will vary in colour but may be brown, blue,
canary yellow or white depending upon the precise circumstances which led to their
formation.
If these oxides are present, it is recommended that you refer to the section on
source removal and cleaning before proceeding, see Section 7.5.
7.4.2 Fitting new filaments
The fitting of new filaments is simply the reversal of the procedure for removing
them. Care should be taken at all stages to ensure that no shorts are introduced
and that the analyser is kept clean.
1. Place and align the new Filament Screen on the source plate mounting posts.
2. Using tweezers, carefully offer the filament plate onto the mounting posts. Be
careful not to touch the source cage with either filament. There is no orientation of
the filament plate required, except that the mounting holes line up with the
mounting posts.
3. Re-fit the two M2 x 4 pan head screws through the filament plate and filament
screen and tighten securely. Do not over tighten.
4. Re-fit each barrel connector in the same orientation as removed, sliding each
barrel connector over the connecting lead and filament post and while holding the
barrel connector firmly with pliers, tighten all screws.
5. Before re-fitting the analyser to your vacuum chamber, carry out Section 7.2 to
check for any short circuits.
6. Replace the analyser into your vacuum housing and again check for shorts or
grounding to the outer vacuum housing.
You are now ready to pump down and continue the operation of your quadrupole.
