For instance, PPM implies "areas per million". If you discover out which the focus of NO2textual content NO _2NO2​ is equal to one ppm, it signifies that if you are taking a "sample" of air and divide it into one million elements, one of these will include NO2text NO _2NO2​. https://cruzfkmmk.blogadvize.com/44581230/rumored-buzz-on-ppm-calculator