For instance, PPM signifies "sections for each million". If you find out that the concentration of NO2textual content NO _2NO2​ is equal to 1 ppm, it means that if you take a "sample" of air and divide it into one million pieces, one of them will include NO2textual content NO https://ppmcalculator26780.tokka-blog.com/37001952/rumored-buzz-on-ppm-calculator