Pure water refers to water that is free of impurities.

Pure water is produced by electrodialysis, ion exchanger, reverse osmosis, distillation and other appropriate processing methods, sealed in containers, and does not contain any additives, colorless and transparent, can be directly consumed. Now the vast majority of water through the filtration system after the water is usually pure water.

Pure water

From an academic point of view, pure water, also known as high-purity water, refers to the chemical purity of the water is extremely high, and its main applications in the biological, chemical and chemical industry, metallurgy, aerospace, power and other fields, but its water purity requirements are quite high, so the general application of the most common or electronic industry. For example, the pure water used in the electric power system, the requirements of the impurity content of low to "micrograms / liter" level.

Physical and chemical indicators of the more important is the conductivity and potassium permanganate consumption. Conductivity is a characteristic indicator of pure water, reflecting the degree of purity of pure water and production process control. As drinking water does not go through the process of deionization and purification, this indicator is not examined. But for pure water "pure" is its most basic requirements, metal elements and microorganisms are too high.

Reference:Baidu Encyclopedia - Pure Water