Carbon Dioxide/Temperature/ Humidity Air Quality Monitor Meter,Wall Mountable CO2 Detector, RH Indoor Air Quality IAQ Sensor, 0~2000ppm Range CO2 Range: 0~2000ppm {2001~9999 (out of scale)} / Accuracy 50ppm 5%rdg (0~2000) / Resolution: 1ppm With CE Marking, passed the standards and had been approved by European Directives for health & safety Temperature Range: -10.0~60.0C (14~140F) /Resolution: 0.1C/F / Accuracy: 0.6C / 0.9F Humidity: Range (0.0~99.9%) / Resolution (0.1%) / Accuracy {3% (10~90%) **5% (others)} Perfect to be used to monitor air quality in schools, office buildings, greenhouses, factories, hotels, hospitals and anywhere that high levels of carbon dioxide are generated Simultaneous triple result, displaying CO2 level, temperature and humidity Stable Non-Dispersive Infrared (NDIR) Sensor for CO2 detection Triple LCD Display and programmable alarms Built-in Non-Dispersive InfraRed (NDIR) sensor that provides long-term &amp; stable monitoring Built-in relay that controls the ventilation system to automatically maintain the CO2 level that you set or specify TWA (Time-Weighted Average) 8 HRS STEL (Short-term exposure limit) 15 Minutes Hospitals, Offices, Schools, Theaters, Indoor Sports Arenas, High Rise Buildings, Indoor Area Quality, Commercial Buildings, Residential Housing, Public Buildings, Demand Controlled Ventilation, Clean Rooms. Poor indoor air quality in rooms can lead to fatigue, lack of concentration and illness (Sick Building Syndrome) due to a high concentration of CO2 level.