Belimo Support Center

Dual-channel (also called dual-beam) technology is self-calibrating by using two infrared beams (NDIR). One reference beam is only activated during recalibration, and the reading of the other constantly used beam is adjusted to match it. ABC (Automatic Baseline Calibration) logic uses a single beam and logs readings over time, and the lowest CO2 reading is assumed to be the outside air baseline. The ABC method cannot determine the actual baseline outside air CO2 if the sensor is utilized in a facility that operates continuously, such as a hospital or nursing home.