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Transpector SPS Operating Manual
6.3.1.1 Foreline Pirani Gauge
A Pirani gauge mounted to the Transpector SPS foreline block monitors the
pressure in the foreline. In the event of a pumping system malfunction, the foreline
Pirani gauge can be used to verify the foreline pressure is <10 Torr. For optimal
pumping system performance, the foreline pressure should be <2.25 Torr.
6.3.2 Turbo Molecular Pump
There are two types of pumping systems: Standard (non-corrosive) and corrosive.
The standard turbo molecular pump is used in both applications.
The corrosive pump configuration is selected for applications such as CVD or Etch
or whenever corrosive gases are being sampled. The purge valve is automatically
opened when the Transpector SPS turbo molecular pump is operating.
The corrosive service high vacuum pump requires 10 to 25 sccm of purge gas flow
through the bearing region to protect the bearings from corrosion and loss of
bearing lubricant by evaporation. The regulator is preset at the factory using a MFC
to produce 10 sccm of nitrogen purge. To produce 10 sccm, the nitrogen regulator
should be set between 10 and 15 psi (gauge).
CAUTION
For the corrosive service turbo molecular pump
(CVD/Etch), nitrogen purge gas is required whenever the
system is operational.
WARNING - Risk Of Electric Shock
The turbo molecular pump must be completely at rest
and the controller power supply must be disconnected
before removing the turbo molecular pump connecting
cable.
