LumaSense Technologies INNOVA 1316A-3 - Manual (Page 11)

Chapter 1
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BE6024-12 1316A-3 Multi Gas Monitor LumaSense Technologies A/S
Instruction Manual Page 11 of 96
The Multi Gas Monitor INNOVA 1316A-3 is delivered as specified by
the Customer.
1.4 NDIR Gas Measurement
The Module VM0102A measures the following sample gas
concentrations: Carbon Dioxide (CO
2
), Carbon Monoxide (CO), and
Ethanol
And the UA1372 is as an example given with an O
2
, and NO sensor
installed.
1.4.1 Ethanol, CO and CO
2
Measurement
The NDIR measurement method uses fixed, non-scanning infrared
light frequencies to characterize Ethanol, CO, and CO
2
gas
concentrations. NDIR absorption profiles are the basis for
measurement. The concentration of a gas volume is a function of the
quantity of gas molecules in the sample. The absorption of infrared
light increases with the number of gas molecules in the light path. As
the concentration of infrared-absorbing gas increases, the
transmission of infrared light decreases. A basic NDIR measurement
system includes the following elements:
Sample
Delivery:
The portion of the gas is transported to the 1316A-3 where particulates are
removed before the gas is introduced to the NDIR module.
Infrared
Source:
An infrared light source produces a wide range of light at frequencies covering the
infrared band and extending into the visible spectrum.
Sample
Cell:
The gas to be measured is transported through a sample cell that allows infrared
light to pass through the sample.
Infrared
Filters:
An optical band pass filter is used to select a specific band of infrared light. The
filter wavelength is based on the gas to be measured. Separate infrared filters are
used in the measurement of Ethanol, CO, and CO
2
gas concentrations.
Infrared
Detector:
Infrared light not absorbed by the sample gas is transmitted to infrared detectors.
The detectors produce an output voltage that is proportional to the measured light.
See figure 1.2