SEKO's comprehensive range of chlorine probes covers most major water-treatment applications. Chlorine is a compound used directly or indirectly in various sectors such as paper, antiseptics, dyes, food, insecticides, paints, petroleum products, plastics, medicines, fabrics, solvents and many other consumer products. It is used to kill bacteria and other microbes in the drinking water supply and in the swimming pools. Chlorine is also used in bleaching wood pulp for paper making, while bleach is also used industrially to remove ink from recycled paper. Free chlorine, chlorine dioxide and total chlorine are usually measured to monitor and control the disinfection of drinking water, recycled water or water in swimming pools. n fact, when chlorine is added to water, it reacts with the organic compounds and metals present in the liquid, forming combined chlorine. Combined chlorine is not active for disinfection.