FPI AQMS-450 carbon dioxide (CO₂) analyzer measures ambient CO₂ concentration by employing Non-dispersive infrared (NDIR) with gas filter correlation (GFC) method technology to realize ppm level CO₂ concentration measurement. 

Principle
Infrared energy emitted by light source is passed through gas chamber containing the air sample, and the quantitative absorption of energy by CO in the sample cell is measured by corresponding detector.

GFC
GFC (Gas filter correlation) technology is utilized to remove interference caused by moisture and other backgrounds.
Two gas filled chambers are mounted on a rotating disc, which pass through an IR beam alternately. The measure chamber is filled with nitrogen while the reference chamber is filled with high concentration CO. IR beam then passes through the sample gas cell. The difference in absorbance is measured and provides a direct output of the gas concentration.

Data storage and analysis
Stored data are easily retrievable through the serial or ethernet port via PC client software, allowing operators to perform predictive diagnostics and enhanced data analysis by tracking parameter trends.