DIYDo It Yourself More sensor for monitoring airborne concentrations of VOCsVolatile Organic Compounds More, NOxIn atmospheric chemistry, NOₓ is shorthand for nitric oxide (NO) and nitrogen dioxide (NO₂), the nitrogen oxides that are most relevant for air pollution. More, O3Ozone More, (and also possible PM2.5Particulate matter with a diameter of 2.5 micrometers or less. Also referred to as fine particles. More)