VISOCOLOR® HE Chlorine: Colorimetric determination of free and total chlorine. Features: • At a pH value of 5 – 6 free chlorine reacts with N,N-diethyl-1,4-phenylene diamine (DPD) to form a red-violet dye. • In the presence of iodide ions the content of total chlorine can be determined, too. (Reaction principle is analogous to APHA 4500CL G & DIN EN ISO 9963-1) Specifications: • Type: high sensitive test kit • Range: 0.0 · 0.02 · 0.04 · 0.06 · 0.10 · 0.15 · 0.20 · 0.30 · 0.40 · 0.60 mg/l Cl2 • Sufficient for: 2 x 160 determinations • Shelf life at least: 24 months • Sea water suitability: yes • Detectable with PF-11: no • The addition of chlorine to swimming pools, water reservoirs and water mains is an approved procedure to rid the water of germs. • With the correct dose harmful microorganisms are destroyed, many impurities removed and the growth of algae is prevented. • However it is imperative that the chlorine content is regularly checked, since excessive chlorine not only impairs the smell and taste of the water but can be hazardous. • One distinguishes between free chlorine and bound chlorine (chloroamines); the sum of both is called total chlorine.