The conductivity meters measure the capacity of ions in an aqueous solution to carry electrical current. Since the ranges in aqueous solutions are usually small, the basic units of measurements are milliSiemens/cm (mS/cm) and microSiemens/cm (µs/cm)

Conductivity is used widely to determine the level of impurities in water supplies for domestic consumption as well as industrial use. Industries that employ this method include the chemical, semi-conductor, power generation, hospitals, food and beverage, mining, electroplating, pulp and paper, petroleum and marine industries.