For instance, PPM implies "components for every million". If you find out the concentration of NO2textual content NO _2NO2​ is equivalent to 1 ppm, it means that if you are taking a "sample" of air and divide it into one million areas, one of them will consist of NO2text NO https://free-ppm-calculator97540.theideasblog.com/37269183/the-free-ppm-calculator-diaries