Large CO2 monitor (NDIR method)Large CO2 monitor (NDIR method) The large screen CO2 monitor is easy to read! You can see the CO2 concentration with numbers, colors, and alarms! Easy to see with the large CO2 monitor! CO2 concentration is shown by numbers, colors, and alarms! *If you use it by plugging it into an outlet, you will need a separate USB adapter. Carbon dioxide measurement range: 400 5000ppm, temperature measurement range: approx. 10 to 60C, humidity measurement range: 0