Pump Operating Procedure - Agilent Technologies VacIon Plus 800 Manual Del Usuario

Technical Information

Pump Operating Procedure

1 Using a clean roughing pump, evacuate the system to the suggested starting
pressure (or lower), as stated in the technical specification. To reach this
pressure the use of an oil free turbo-molecular roughing pump is
recommended.
2 Connect the ion pump control unit to a suitable power source and switch the
controller on.
3 When starting the ion pump, a slight pressure increase is normal, since the
internal components are heated and outgassed. Leave the roughing pump
connected to the system while starting the ion pump. This will make the startup
faster and easier.
4 Switch on the high voltage and observe the current and voltage behavior on the
controller display. The fastest starting is obtained using a high applied voltage
(e.g. 7 kV). The applied voltage may be reduced later, when the pressure will be
lower, in order to optimize the pumping speed. This operation is done
automatically by Agilent controllers when set in "STEP" mode.
5 If the ion pump has been started at too high pressure, typically the voltage will
be of some hundred Volts. If the voltage remains constant at these values, in
order to avoid pump overheating we suggest turning it off and start it again at a
lower pressure (see the paragraph "Use"). If the ion pump is started at the
suggested pressure, the voltage will quickly increase to full voltage as the pump
starts operating. The current will start at several milliamps and slowly decrease
to microamps or nanoamps as low vacuum pressure is achieved.
6 When starting the ion pump for the first time, if the voltage decreases instead
of increasing, switch off the ion pump, keep the roughing pump running and
start the ion pump again after a while.
7 When the pump reaches its full operating voltage, the roughing valve can be
closed.
8 If the pump does not start after 30 minutes of pumping, see the section PUMP
TROUBLESHOOTING.
9 Once the pump reaches its base pressure with stable voltage and current, the
ion pump and the system may be baked at high temperature as per the
indications in the section titled BAKEOUT OPERATION.
Agilent VacIon Plus 800 User Manual 221