LumaSense Technologies INNOVA 1316A-2 - Manual (Page 13)

Chapter 1
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BE6021-11 1316A-2 Multi Gas Monitor LumaSense Technologies A/S
Instruction Manual Page 13 of 97
Fig.1.4 The Optics of the NDIR Module.
Sample Cell
The sample cell is a gold-coated glass chamber that provides a
means for the infrared source to pass through the sample gas.
Infrared-transparent sapphire windows are provided at each end of
the cell. A microprocessor controlled transducer and thermistor
provide measurement compensation for sample gas temperature and
pressure variances. Sample gas exits the cell at the end opposite the
IR source and is directed to the UA1372 manifold for O
2
or O
2
/NO
measurement .
Optical Block
Infrared light not absorbed by the sample gas is transmitted to the
optical assembly. The remaining light is directed to the band pass
filters and on through to the quad detector.
The filter wavelengths are optimised to match the absorption spectra
of Freon's and Carbon Dioxide.
The filter associated with Freon's is centred on 8.73 µm (1145 cm -1 ),
and the filter associated with Carbon dioxide is centred on 4.43 µm
(2260 cm -1 ), see Figure 1.3 .
In the measurement chamber the three beams, which differ in
wavelength frequency, each excite their respective gas (if present).
The absorption of the incident light will be registered by the
Detector.
IR
SOURCE SAMPLE CELL
BAND
PASS
FILTERS
ELECTRONICS