Varian 4000 GC, Hardware Operation Manual

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Electronics
HIGH VOLTAGES INSIDE. No user serviceable parts under screw-attached
covers. Contact your local Varian, Inc., service representative for instrument
repair and service.
The electrical functions of the 4000 MS are distributed among eight boards (see
block diagram) each carrying out some specific functions. In some cases, the
boards are located as close as possible to the associated part of the
spectrometer. The RF coil plays a part in generating the trapping field RF and is
a power entry subsystem in the back of the instrument. The functions of the
boards are as follows:
•
Controller Board – controls spectrometer operations and acquires data
generated by the system.
•
Power Board – generates all power sources for the instrument, controls
the temperature of heated zones, routes signals between other boards
and drives all solenoid valves.
•
Lower Manifold Board – drives various source voltages and controls
filament operation.
•
Upper Manifold Board – contains circuitry that handles supplemental
excitation waveforms and trapping field dipole switching.
•
RF Generator Assembly – generates and controls the RF trapping field.
•
Ion Detector Board – has the circuitry for the Multiplier and Ion Gauge,
both of which detect ions in the system.
•
Ion Amplifier – an electrometer that amplifies the ion signal.
•
Electronic Flow Controller – the module that controls the flow of the
helium damping gas.
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