LumaSense Technologies INNOVA 1316A-2 - Manual (Page 11)

Chapter 1
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BE6021-11 1316A-2 Multi Gas Monitor LumaSense Technologies A/S
Instruction Manual Page 11 of 97
The NDIR Module and the Electrochemical Sensors are to be specified
prior to purchase.
The Multi Gas Monitor INNOVA 1316A-2 is delivered as specified by
the Customer.
1.4 NDIR Gas Measurement
The Module VM0101A measures the following sample gas
concentrations: Carbon Dioxide (CO
2
) and Freon either with reference
to FREON1 or FREON2 (selectable from the BZ6013 Application
Software)
And the UA1372 is as an example given with an O
2
and NO sensor
installed.
1.4.1 Freon and CO2 Measurement
The NDIR measurement method uses fixed, non-scanning infrared
light frequencies to characterize Freon 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-2 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 Freon 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