e-Vision and e- LP101013.100 – 01 January 2004
MKS Instruments, Spectra Products
24
Routinely there is only one area of the analyser that requires any maintenance, this
is the ion source. The ion source contains two filaments, only one of which will be
in use at any one time. The filament is heated to approximately 2000 deg K at
which temperature it emits electrons, which are used to produce the ions required
by the quadrupole filter. At this high temperature, there are two deleterious effects.
The filament material slowly evaporates and condenses upon the surrounding
surfaces. This effect is extremely slow but would require, from time to time, the
cleaning of the surrounding source plates and ceramics and the replacement of the
filaments.
The second effect is similar to the first except that the vacuum, under which the
source is operating, has either a high oxygen or water content. Then instead of
metal being deposited upon the surrounding source plates, layers of metal oxides
are deposited. Being insulators, these have a far more noticeable effect upon the
performance of the source and therefore a more frequent cleaning program should
be adopted.
CAUTION
THE QUADRUPOLE’S FILTER IS ACCURATELY
ALIGNED BY
SKILLED PERSONNEL USING
SPECIALIST TOOLS AND JIGS.
UNDER NO CIRCUMSTANCES SHOULD THE FILTER ASSEMBLY BE
DISMANTLED.
IF YOU ARE IN ANY DOUBT WHEN SERVICING YOUR ANALYSER,
PLEASE
CONTACT YOUR LOCAL SERVICE CENTRE.