Inficon Ecotec E3000, Техническое руководство

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2-2
How the Instrument Works
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2.2 Description of the Subassemblies
2.2.1 Backing Pump
A diaphragm pump in the Ecotec E3000 serves as the backing pump. All data and
further information on this pump are given in the Operating Instructions of the pump.
The backing pump generates the fore pressure required for operation of the turbo
molecular pump and sucking in of the gas through the sniffer line.
2.2.2 Turbo Molecular Pump (TMP)
Built into the Ecotec E3000 is a turbo molecular pump with upstream compression
stage. The turbo molecular pump generates the high vacuum necessary for
operation of the mass spectrometer, whereas the compression stages permits
relatively high backing pressures without impairing the ultimate pressure in the mass
spectrometer. The TMP has a side connection. Thus a part of the taken in gas is
pumped through the TMP into the first stage of the diaphragm pump. This gas load
prevents the accumulation of water vapour in the diaphragm pump.
2.2.3 Mass Spectrometer
The Transpector
TM
mass spectrometer is composed of the ion source, the separator
and the ion collector. The ion source ionizes neutral gas particles and generates an
ion beam. The positively charged ions are accelerated out of the ion source and then
enter the Quadrupole field. This field acts like a filter. Only the ions to which the
system has been adjusted are able to meet the separating conditions and arrive at
the ion collector, where their presence can be measured as a current by an
electrometer amplifier. This current is the output signal which is then used to
calculate the leak rates. Two cathodes have been integrated within the ion source. If
one cathode fails the other is selected automatically.
2.2.4 Quadrupole Supply
This subassembly generates all the voltages and currents required for operation of
the mass spectrometer. Faults in the mass spectrometer are detected and signalled
to the control assembly. The control assembly monitors the mass spectrometer
supply.
2.2.5 Control
The control assembly (microprocessor) is the central assembly of the Ecotec
E3000’s electronics. All other subassemblies are controlled and monitored by this
assembly. The microprocessor which is located here is thus continuously informed
about the status of the entire Ecotec E3000 and can respond accordingly. In order to
accept commands from the operator and to output measured values and messages,
the control subassembly is linked to the display unit.