The CDD4 series uses a highly accurate and reliable Non‑dispersive Infrared (NDIR) sensor in an attractive, low profile enclosure for room applications to monitor CO2 , levels. A linear analog signal output of 4‑20 mA, 0‑5 or 0‑10 Vdc is provided for connection to a building automation system. Optional features such as temperature sensor, setpoint adjustment, manual override and adjustible relay output are available.