4-13
Model 979 Series Helium Mass Spectrometer Leak Detector
DRAFT 9/15/03
4.3.3 Removing the Ion Source
WARNING
Store the Ion Source in a cool, dry area in a tightly sealed
container. Wash hands thoroughly after handling the Ion Source
and especially before smoking or eating.
CAUTION
Use powder-free butyl or polycarbonate gloves to prevent skin
oils from getting on vacuum surfaces.
NOTE
The ion source is typically replaced during the normal
maintenance procedure. A new and clean ion source provides
optimum sensitivity and system performance.
See Section 4.4 “Ion Source Replacement Outside of Annual
Maintenance” on page 4-20 when replacing the ion source
outside of annual maintenance.
1. Remove the 4 Phillips screws that hold the ion source header piece, repeating steps 1, 2,
and 3 (Section 4.3.2 “Removing the Button TC” on page 4-11) to release the ion source.
2. Remove the ion source from the spectrometer tube body (Figure 4-12).
Figure 4-12
Removing the Ion Source
NOTE
Dark carbon-like deposits around the ion source filament and/
or a rainbow-like discoloration on the inside walls of the ion
source cavity indicate that the spectrometer tube has been
operated at too high a pressure. This can occur from a system
pressure leak or from transferring into test at too high a
pressure.
Summary of Contents for 979 Series
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