As an example, PPM signifies "sections for each million". If you discover out which the focus of NO2text NO _2NO2​ is equivalent to one ppm, it means that if you take a "sample" of air and divide it into one million parts, one of them will encompass NO2textual content NO https://jaredxskbq.bloggazzo.com/35644788/ppm-calculator-can-be-fun-for-anyone