CAI 700 NDIR, Руководство оператора

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700 NDIR Analyzer 6-20-2017
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Operating Principle
The CAI 700 NDIR/O
2
analyzer is based on the infrared absorption characteristics of
gases. Using a single infrared beam to measure gas concentrations, this analyzer delivers
highly stable and reliable results.
A single infrared light beam is modulated by a chopper system and passed through a
sample cell of predetermined length containing the gas sample to be analyzed. As the
beam passes through the cell, the sample gas absorbs some of its energy. The attenuated
beam (transmittance) emerges from the cell and is introduced into the front chamber of a
two-chamber infrared microflow detector. The detector is filled with the gas component
of interest, and consequently the beam experiences further energy absorption. This
absorption process increases the pressure in both chambers.
The differential pressure between the front and rear chambers of the detector causes a
slight gas flow between the two chambers. This flow is detected by a mass-flow sensor
and is converted into an output signal.
The 700 NDIR/O
2
analyzer’s oxygen channel utilizes either the paramagnetic or
electrochemical fuel-cell method to determine the percent level of oxygen contained in
the sample gas. The oxygen level is displayed on the LCD panel in percent concentration.