MKS Instruments UK Ltd
Cirrus2 Hardware Manual – SP101017.100 June 2011
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Once the turbo pump is up to speed, the indicator will change to green in the software interface and on the front panel of
the Cirrus2.
Starting the Quad
The quadrupole’s filaments are interlocked with the internal pressure gauge, you will only be able to start the filament
once the chamber has reached its operating pressure.
Baking
Before you can start to use the system properly, it will need to be run for sufficient time to allow the background peaks to
drop. This amount of time can be significantly reduced by baking the system.
From the Heat/Bake pull-down list, choose the Bake option. A dry, inert gas should be flushed continuously through the
capillary inlet during bake out. The quadrupole should be running with the filament on but only using the faraday detector.
The multiplier detector will be unavailable during baking
The total pressure should gradually start to rise as the system outgases and you should bake the system at least until the
pressure starts to fall. In normal operation an initial bake of at least 24 hours is required, although in general the longer
the system is baked the better.
To improve the background further, it is recommended that you run and degas both filaments. The amount of time spent
in reducing the background peaks depends entirely on the application and is left to the discretion of the customer. If the
Cirrus is switched off, it will vent to atmosphere introducing water vapour and should be baked again.
