The HI3831F is a chemical test kit that uses the DPD method to measure free chlorine. The HI3831F is supplied complete with all of the reagents and equipment necessary to perform approximately 50 tests.

• Pre-made reagents for ease of use
• Color comparison cube for simple determination
• Complete setup:All required materials are included with the test kit, such as the color comparison cube, and reagent dropper bottles

Disinfection is a process of killing disease-causing organisms (or pathogens). Chlorine (Cl2) is a very desirable disinfectant because, when mixed with pure water, it reacts to form hypochlorous acid (HOCl) and hydrochloric acid (HCl). HOCl (free active chlorine) is the most effective form of chlorine for the disinfection of pools, spas, and drinking water.

Drinking water municipalities add elemental chlorine to the water supply as chlorine gas, liquid sodium hypochlorite, or dry calcium hypochlorite. In water, these form free chlorine ions, which destroy disease-causing pathogens, reduce odor, eliminate bacteria and help to remove unwanted elements. The USEPA requires that residual disinfectant is present in finished drinking water to ensure there is disinfectant available throughout the distribution system, with chlorine acting as one of the disinfectants that provide said residual. However, the EPA has also set a maximum contaminant level of 4.0 mg/L for free chlorine due to potential health effects above this level.