CO2 Detectors are used to detect dangerous levels of CO2 in breweries, laboratories and cellars. CO2 levels of 1.5% can already cause hyperventilation and headaches. 10% CO2 levels can lead to death. Our portable and fixed CO2 monitors can detect the changes in the levels of carbon dioxide (CO2) within an enclosed area. The infrared CO2 sensor continuously measures CO2 levels and displays the reading on a clear backlit display. Units also provide a loud audio alarm. The detectors are manufactured by Crowcon, one of the UK's leading gas detection companies. (Did you look for carbon monoxide detectors?)