New Advances in Non-Dispersive IR Technology for CO ₂ Detection

This paper discusses new technology developments in carbon dioxide (CO₂) detection using Non-Dispersive Infrared (NDIR) techniques. The method described has successfully been used in various applications and environments. It has exhibited extremely reliable long-term stability without the need of routine calibration. The analysis employs a dual wavelength, differential detection approach with compensating circuitry for component aging and dirt accumulation on optical surfaces. The instrument fails “safe” and provides the operator with a “fault” alarm in the event of a system failure. The NDIR analyzer described has been adapted to NASA Space Station requirements and a breadboard furnished under NASA contract NAS9-17612.