By way of example, PPM suggests "elements for each million". If you discover out which the concentration of NO2text NO _2NO2​ is equivalent to one ppm, it signifies that if you take a "sample" of air and divide it into one million sections, one of them will include NO2textual content https://josueqohyn.affiliatblogger.com/88796392/the-best-side-of-free-ppm-calculator