simonstirnemann7 years ago+110Why does the NWS01-EU indicate a carbon monoxide level of 500 ppm? According to Wikipedia, that would already be harmful? Thank youShow in original language (German)Brimstone7 years ago+110Here, however, the carbon dioxide level (CO2) and not carbon monoxide is measured. 500PPM is approximately the value of the outside air in the city. -> http://www.gesundes-haus.ch/lueftungsa...Show in original language (German)Comment