For instance, PPM indicates "areas for each million". If you discover out which the focus of NO2text NO _2NO2​ is equivalent to one ppm, it means that if you are taking a "sample" of air and divide it into 1,000,000 elements, one of them will encompass NO2text NO _2NO2​. Rijk https://perryu221pyf0.bloggerbags.com/profile