HPQ2-IP SP101009.102 – 10 October 2012
MKS Instruments, Spectra Products
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7. Analyser Maintenance
7.1 General Overview
The HPQ2-IP quadrupole analyser is the front end of your mass-spectrometer, it
produces electrical signals which when presented to your electronics enable them to
display in a meaningful fashion the content of either your vacuum system or of
some other "interesting" gasses introduced via an inlet.
Before embarking on any analyser maintenance you should have all the necessary
parts and tools ready. If you are in any doubt about the work that you wish to
undertake please contact your local Spectra facility, ask for the service department
and have the serial number of the analyser ready. The serial number is engraved on
the analyser flange and will begin with the letters “LM”.
The HPQ2-IP analyser can be broken down into four separate areas by virtue of
their function.
1. The ion source or ioniser
This is located at the top (furthest from the flange) of your analyser and its function
is to take a representative sample of molecules and atoms from your vacuum
chamber, convert them into ions and present them to the quadrupole filter.
2. The quadrupole filter
This is the centre section of your analyser. Its function is to take the ion beam
generated in the source and separate the various ions by their mass to charge ratio
(m/e) and present the single selected m/e to the collector.
3. The collector
This area of your quadrupole analyser is "hidden" inside the flanged housing. Its
function is simply to convert the filtered ion beam presented by the quadrupole filter
into a small electrical current which can be passed to the electronics for
amplification and subsequent display to the outside world.
4. The flanged housing
This is the only part of your analyser that you will see under normal operating
conditions. Comprising of an industry standard 2.75" Conflat® flange with an
electrical feedthrough which carries the various supplies and signals to and from the
quadrupole analyser.