GE b30, Technical Reference Manual

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B30 Patient Monitor
8-8
Document no
.
2044677-001
Figure 4 Gas tubing layout
3.2.2 MiniC measuring unit
The miniC measuring unit is a non-dispersive infrared analyzer measuring absorption of the
gas sample at 4.2 to 4.3
µ
m infrared wavelength, which is selected using an optical narrow
band filter. The IR lamp is a filament surrounded by thermal isolation. There is a hole in the
isolation, passing the radiation to a conical measuring chamber with 3 mm length. From the
sample chamber, the radiation goes into a thermopile detector with an optical filter in front of
it.
The temperature sensor measures the miniC
measuring unit's temperature and it is used for
temperature compensation.
The miniC measuring unit includes a miniC flexible board, which connects the thermopile signal
and the temperature sensor signal to the CPU board.
Figure 5 MiniC measuring unit
Gas out
Side flow
Main flow
Sample line
Room air
Zero
valve
Mini
D-fend
MiniC
Diff.
Pressure
Sensor
Diff.
Pressure
Sensor
Pump
Filter
Abs.
Pressure
Sensor
mi
ni
c_fem_gas
tubi
ng.vsd