Pieces for every million (ppm) denotes the number of models of the material contained in 1,000,000 units of An additional substance. It's a ratio expressing the concentration of 1 substance within just Yet another and is particularly broadly accustomed to measure the purity of water, air, foodstuff goods, plus more. https://ppmcalculator82479.dailyblogzz.com/37306255/a-review-of-online-ppm-calculator