The 8600 carbon dioxide (CO2) monitor measures temperature, humidity, and ventilation accurately and easily, using a fast, simple calibration procedure, says the company. The dual-beam Absorption Infraredâ„¢ gas sensor ensures long-term stability and durability, the company states. It has a large digital display with dual readings, which displays CO2 readings of 0 to 10,000 ppm and ventilation rates in cfm per person. This hand-held monitor offers up to 80 hours of use, using four AA batteries or can be used with an AC power adapter. It comes with a flip-out stand for desktop monitoring.