The GS and TA Series CO2 sensors use NDIR technology to determine the CO2 level. NDIR uses an infrared light source
through a patented waveguide that filters the infrared 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
does not have unoccupied periods of operation.