Inlet Gases Hardware - Thermo Scientific LTQ Series Hardware Manual

Forepumps
Convectron Gauge
Ion Gauge

Inlet Gases Hardware

Vent Valve
Thermo Scientific
The LXQ mass spectrometer has one forepump and the LTQ XL and Velos Pro mass
spectrometers have two forepumps. Forepumps create the vacuum necessary for the proper
operation of the turbomolecular pump. The forepumps also evacuate the ion transfer tube
region of the vacuum manifold.
The nondetachable power cords of the forepumps plug into the auxiliary power outlet labeled
Mech. Pumps on the power panel
controls this outlet, not the electronics service switch.
CAUTION Always plug the forepump power cords into the outlet labeled Mech. Pumps on
the right side of the mass spectrometer. Never plug them into a wall outlet.
The LXQ and LTQ XL mass spectrometers contain a Convectron™ gauge that measures the
pressure in the ion transfer tube in the vacuum manifold and the foreline, which connects the
turbomolecular pump and the forepump. The source printed circuit board (PCB) monitors
the pressure measured by the vacuum gauge.
An ion gauge measures the pressure in the analyzer region of the vacuum manifold and is also
used for vacuum protection.
The inlet gas hardware controls the flow of damping gas, sheath gas, auxiliary gas, sweep gas,
and air (during venting) into the mass spectrometer.
The vent valve (Figure 24
been filtered through a sintered nylon filter. The vent valve, a solenoid-operated valve, is
closed when the solenoid is energized.
The vacuum manifold vents when the mass spectrometer no longer receives external power, as
with a power failure or by turning off the Main Power switch. Power is briefly provided to the
vent valve after losing external power to protect against the accidental loss of power. When
power to the vent valve solenoid shuts off for more than a very brief period of time, the vent
valve opens and the manifold vents to filtered air.
(Figure 8 and Figure 9
Figure 24 on page 30
on page 30) allows the vacuum manifold to be vented to air that has
2
Functional Description
on page 14). The Main Power switch
shows the ion gauge port.
LTQ Series Hardware Manual
Mass Spectrometer
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