The GS and TA Series CO2 sensors use NDIR technology to determine the CO2 level. NDIR uses an infra-red light source through a patented wave guide that filters the infra-red signature of the CO2 gas to a thermopile receiver. Automatic background calibration (ABC logic) ensures years of calibration free performance when enabled. ABC logic essentially uses the unoccupied CO2 level over an extended period of time to adjust the calibration of the sensor. ABC logic should not be enabled if the facility doe not have unoccupied periods of operation.
GreenTrol CO2 sensors are available in wall and duct mount models, with some models having additional sensing capability.