For instance, PPM usually means "components for every million". If you discover out which the concentration of NO2text NO _2NO2​ is equal to 1 ppm, it signifies that if you're taking a "sample" of air and divide it into 1,000,000 areas, one of these will encompass NO2text NO _2NO2​. PPT https://free-ppm-calculator96283.blogrenanda.com/43230224/the-single-best-strategy-to-use-for-ppm-calculator