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Transpector CPM Operating Manual
4.3.2.1 Foreline Subsystem
The foreline subsystem components include a flexible foreline hose of various
lengths (
10 m), a foreline Pirani gauge, and a diaphragm foreline pump.
The Foreline Pump produces base pressures (no gas flow) of 2 Torr, significantly
less than the 10 Torr needed for the Turbo Molecular Pump operation. The 2 Torr
operating pressure for the foreline is in the viscous gas flow regime such that the
foreline does not require a large diameter. The inside diameter of the foreline is
6 mm (1/4 in.) which produces a 2 Torr pressure drop across a 10 m length of
foreline at 20 sccm of gas flow.
The foreline Pirani gauge can be used to troubleshoot pumping system problems
and to verify that the turbo pump is being backed properly.
4.3.3 Heater(s) Subsystem
The heaters are dual temperature (150°C and 90°C), dual element silicone rubber
pad heaters with silicone rubber foam insulation.
The CPM controller supplies power to the heaters.
Heaters are software controlled at low temperature (90°C) or high temperature
(150°C).
WARNING - High Temperature
During or immediately after bakeout, the heating jacket
and metal surfaces in the vicinity of the heating jacket are
hot. These surfaces exceed 100°C at the maximum
ambient operating temperature (50°C), and will cause
burns if touched.
4.3.4 CPM Controller Subsystem
The CPM controller contains all of the AC components, the AC-DC converter which
supplies the +24 V (dc) for the Transpector, the Foreline Pump, the Turbo
Molecular Pump controller, and valve solenoids.
The AC-DC converter accepts input voltages ranging 90-240V (ac). The output is
24 V (dc) @ 12A. The output is supplied through the CPM controller interface cable
to the Transpector electronics.
The heater drive circuit controls the AC voltage to the heaters. The heaters are
interlocked and will not turn on if the pump is not up to speed or if there are any
faults.
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