Pump Used In Presence Of Magnetic Fields; Accessories And Spare Parts - Agilent Technologies TV 902 Bedienungshandbuch

18 Technical Information

Pump used in Presence of Magnetic Fields

If the temperature sensor is disconnected, the pump will not start. To
prevent damage to the pump when the temperature exceeds 60 °C,
the sensor automatically cuts out the power supply.

Pump used in Presence of Magnetic Fields

Magnetic fields induce eddy currents in the rotor of a turbomolecular
pump that tend to oppose to its rotation. The result is increased
electrical power consump-tion by the motor, most of which is
dissipated in the rotor. Since the rotor is not in contact with the
stator the above power can leave the rotor mainly by radia-tion and
hence the rotor may be overheated while static parts of the pump
remain cool. This effect is strongly dependant from the inten-sity,
time function and distribution of the magnetic field. In general,
therefore, an increase in pump current can be expected. If this
increase is lower than 50 % of the current value drawn by the motor
in high vacuum opera-tion, no particular problem should be
expected. However if the effect is greater, than the case should be
carefully reviewed by Agilent's special-ist. As a matter of fact, in case
of high magnetic fields, also important forces might be generated and
applied to the rotor.

Accessories and Spare Parts

Description
Mains cable NEMA Plug, 3m long
Mains cable European Plug, 3m long
286/292
Part number
969-9958
969-9957
TV 902 Navigator User Manual / 87-900-999-01 (A)