Start-Up And Operation Of The Vacion Plus 800; Preliminary Actions Before To Switch On The Pump - Agilent Technologies VacIon Plus 800 Manual Del Usuario

Instructions for Use

Start-up and operation of the VacIon Plus 800

All the instructions for the correct use of the VacIon Plus 800 pumps are contained
in this manual and in the relevant pump control unit manual. Read these manuals
carefully before using the pump.

Preliminary actions before to switch on the pump

Rough pumping down to a pressure equal or lower than 1E-5 Torr (mbar) for the
Diode version - 1E-4 Torr for the StarCell version - is recommended for the most
rapid starting and in order to preserve pump lifetime. Typically this pressure level
can be easily achieved by means of a turbomolecular pump, supported by a primary
pump, preferably oil free.
The ion pump can in principle be started also at pressure higher than the one we
recommend, but this prolonged practice can affect the pump lifetime. In the past
the need to start the ion pump at high pressure was due to the fact that it was
directly connected to the primary pump; thanks to the invention of turbomolecular
pumps, this is no longer necessary.
Hygroscopic deposits - that are natural consequence of exposure to air- and
hydrogen absorption into the titanium cathodes – phenomenon connected to the
physical working principle of the ion pump - may cause starting times to increase
with age. In fact the pump heating that takes place at its start-up causes release of
the water vapor and some previously pumped hydrogen; thus, the starting time may
be lengthened.
202 Agilent VacIon Plus 800 User Manual