Measure ambient CO2, temperature, relative humidity, dew point, wet bulb, CO, and calculate percentage outside air! The TPI 1010a Indoor Air Quality (IAQ) Meter is a state of the art, easy to use tester designed to provide you with the necessary measurements to monitor and make adjustments to air handling devices.The 1010a IAQ meter uses state of the art sensors to measure carbon dioxide (CO2), and temperature. Calculate percent outside air to maintain acceptable CO2 levels in buildings and work spaces Measure and display Carbon Dioxide (CO2) and Carbon Monoxide Measure ambient air temperature Measure relative humidity, dew point and wet bulb Log up to 4,000 readings in 1 second to 23 hour 59 minute intervals Download to a computer using the A368 USB cable Print via I/R to optional printer (Model A740)Please see Technical Information below for more information on this product.