Deionised water by ion exchange
The term DI water stands for fully deionised water. Experts also often refer to DI water as desalinated water or demineralised water.
DI water is frequently obtained from drinking water (spring or tap water) using ion exchangers, by removing the minerals in the water, such as salts and ions. Tap water is used as raw water for smaller quantities. For larger quantities for industrial use it is common for surface or well water to be used, depending on the application.
One of the parameters for measuring the quality of DI water is its electrical conductivity, which is given in micro-Siemens per centimetre (µS/cm). The quality requirements for DI water can vary considerably. DI water is used in a wide range of industrial applications, for example as a heat transfer medium in the coolant circuits of power stations, for metal cleaning systems, humidifiers, rinsing baths and electroplating process baths as well as for supplying steam boilers and steam turbines. Over and above this, DI water is also used in hospitals, laboratories and in the medical technology sector.