The Extech EA80 is a comprehensive indoor air quality (IAQ) meter that measures CO₂ (0–6000 ppm), temperature (–4 to 140°F), relative humidity (10–95% RH), dew point, and wet bulb. It features automatic datalogging of up to 20,000 continuous readings or 99 manual sets, with time-stamped Max/Min values and user alarms. Includes PC software and RS-232 cable for data analysis—ideal for schools, offices, hospitals, and greenhouses.