Selecting the right CO₂ sensor depends on the application. If the monitored environment experiences periodic exposure to background CO₂ levels, the optimal solution will be a single-channel NDIR sensor utilizing ABC Logic™. This sensor will provide in-situ automated recalibration for the life of the sensor, improving performance and reducing the cost of ownership. If the monitored environment is continually occupied or not expected to see diurnal CO₂ concentration cycles (such as hospitals, detention facilities, or indoor agricultural structures), a dual-channel NDIR is necessary. Without periodic exposure to background CO₂ levels, firmware-based algorithms cannot be reliably deployed for drift compensation. While the hardware-based reference inherent in the dual-channel NDIR sensors can provide excellent drift compensation, recalibration will eventually be required for these NDIR sensors in order to retain factory-performance specifications.