For instance, PPM means "components for each million". If you find out which the focus of NO2text NO _2NO2​ is equal to 1 ppm, it implies that if you're taking a "sample" of air and divide it into 1,000,000 components, one of them will encompass NO2textual content NO _2NO2​. Sections https://elliottxzzzs.get-blogging.com/37254198/free-ppm-calculator-options