One example is, PPM signifies "pieces for every million". If you find out which the focus of NO2textual content NO _2NO2​ is equivalent to one ppm, it ensures that if you take a "sample" of air and divide it into one million components, one of these will encompass NO2text NO https://zionaecxt.acidblog.net/67703152/the-basic-principles-of-free-ppm-calculator