Supco's IAQ series measure carbon dioxide (CO2), temperature and humidity with dew point and wet bulb. Ideal for air quality diagnosis, they can be useful in identifying sick building syndrome due to high levels of CO2. Features: visible/audible (80db) CO2, alarm, large triple function LCD display, min/max, average recall, alarm output relay, long time drift compensation, non-dispersive infrared (NDIR) sensor, 12 VDC power adapter (120 VAC supplied), TWA (time-weighted average) 8 hrs, STEL (shor t-term exposure limit) 15 minutes. Applications: residential, offices, restaurants, warehouses, garages, green houses. Range: 0 - 2000 ppm. Resolution: 1 Ppm. Accuracy: +/-75 ppm +/-5 percent rdg (0-2000 ppm) Not specified for out of scale. Pressure Dependence: +1.6 percent Reading Per Kpa Deviation From Normal Pressure, 100Kpa. Temperature - Range: 14 To 140 degree F (-10.0 To 60.0 degree C), Resolution: 0.1 degree F (0.1 degree C), Accuracy: +/-0.9 degree F (+/- 0.6 degree C). Humidity - Range: 0.0 to 99 percent Non-Condensing, Resolution: 0.1 percent, Accuracy: +/-3 percent (10 to 90 percent ) +/-5 percent (others). Warm Up: 30 seconds. Operating: +32 to 122 degree F (0 to 50 degree C) 0-95 percent RH Non-Condensing. Storage: -4 to 140 degree F (-20 to 60 degree C) 0-99 percent RH Non-Condensing. Power: 4 AA batteries (Included).