Emerson Rosemount 370XA, System Reference Manual

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370XA Gas Chromatograph System Reference Manual
APRIL 2014 7P00370-H01
2 - 11
5. Sample shut-off valve
Shuts off the flow of gases to the sample loop for the first five
seconds of an analysis to allow the sample loop to equalize to
atmospheric pressure through the sample vent. This ensures
that a consistent amount of sample gas is injected into the
analytical columns each analysis cycle regardless of the
sample pressure or flow.
NOTICE
It is good practice to replace the diaphragm of the sample shut-off valve whenever
the analytical valve diaphragms are replaced.
6. Manifold assembly
Most of the components of the analytical oven are mounted on
the manifold, which also contains a multi-layered "printed flow-
path board" (PAFB) that replaces the interconnecting tubing
that traditionally exists between the valves, columns,
solenoids, and detectors.
7. Intelligent module board
To facilitate easy replacement of the maintainable module, its
operating and calibration settings are stored on the intelligent
module board (IMB). When a new maintainable module is
installed, it downloads these settings from the IMB. When the
settings are changed, the new configurations are uploaded to
the IMB.
8. Stream selection solenoids
The sample gas stream to be analyzed is selected by a two-
way isolation solenoid. Each stream has a unique stream-
selection solenoid. A maintainable module can have up to
three stream-selection solenoids and one calibration solenoid.
9. Carrier gas pressure sensor
Measures the carrier gas pressure as a part of the electronic
pressure control.