This Desktop CO2 Meter is used to monitor air quality in schools, office buildings, greenhouses, factories, hotels, hospitals, and anywhere that high levels of carbon dioxide are generated. It uses a maintenance-free NDIR sensor and datalogs up to 5333 points for each parameter that can be downloaded to a PC using the included Windows-compatible software. Air Quality is displayed in ppm with Good (380 to 420ppm), Normal (1000ppm) indication. Measurement ranges are 0 to 9,999ppm (CO2), 14 to 140°F (-10 to 60°C) for Air Temperature and 0.1 to 99.9% for Relative Humidity. It features Min/Max CO2 value recall, Year/Month/Date/Time display, and an Automatic Baseline Calibration (minimum CO2 level over 7.5 days) or manual calibration in fresh air. Comes complete with AC adapter.