Such as, PPM means "areas for every million". If you find out that the focus of NO2textual content NO _2NO2​ is equal to 1 ppm, it ensures that if you are taking a "sample" of air and divide it into 1,000,000 elements, one of these will consist of NO2text NO _2NO2​.Pieces For each Million (PPM) can be a unit of focus made use of to explain real