GE b30, Technical Reference Manual

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B30 Patient Monitor
8-6
Document no
.
2044677-001
3.2.1 Gas sampling system
The sampling system draws a gas sample to the analyzer at a fixed rate.
The gas sampling system samples the measured air to the module, and removes water and
impurities from it. A sampling line is connected to the water trap. The pump draws gas through
the sampling line to the gas measuring unit. After the measurement, the gas is exhausted from
the sample gas out connector.
The sample flow is nominally 150 ml/min.
Figure 3 MiniC block diagram
Mini D-fend
TM
The sample is drawn through the sampling line. The gas then enters the module through the
water trap, where it is divided into two flows, a main flow and a side flow. The main flow goes
into the analyzer. This flow is separated from the patient side by a hydrophobic filter. The side
flow creates a slight subatmospheric pressure within the Mini D-fend water trap which causes
fluid removed by the hydrophobic filter to collect in the bottle.
Zero valve
The main flow passes through a magnetic valve before proceeding to the analyzer. This valve
is activated to establish the zero point for the MiniC measuring unit. When the valve is
activated, room air is drawn through a filter into the internal system and the gas sensor.