Sections per million (ppm) denotes the number of units of the compound contained in 1,000,000 units of another substance. It is a ratio expressing the focus of 1 material inside of An additional and is also broadly utilized to evaluate the purity of h2o, air, food items solutions, plus more. https://caidenxqdny.bloggactif.com/38097112/the-5-second-trick-for-online-ppm-calculator