For example, PPM means "sections for every million". If you discover out the focus of NO2textual content NO _2NO2​ is equal to 1 ppm, it signifies that if you're taking a "sample" of air and divide it into 1,000,000 pieces, one of them will include NO2text NO _2NO2​. PPT means https://pikn083mrs9.blogozz.com/profile