Macherey-Nagel test strips for free and total chlorine, in 4 presentations covering different measuring ranges.
91339
91354
91360
91317
A semi-quantitative test strip for free and total chlorine, the active disinfectant in treated water. Dip it, wait the stated time, and compare the pad against the colour scale on the tube.
Too little and the water is not disinfected; too much and it corrodes pipe, irritates skin and ruins taste. The working window is narrow and it drifts all day, because chlorine is consumed as it works and evaporates in the sun.
A strip gives a range, not a figure. That is enough for the great majority of decisions — dose or do not dose, discharge or hold, keep running or stop — and it gives the answer where the sample is, in about a minute, with no instrument to calibrate and nothing to carry back to a laboratory.
When a number has to be defensible — a regulatory report, a dispute, a limit you are close to — a photometer or a laboratory method is the right tool. The strip's job is to tell you whether you need one.
Read the strip immediately: chlorine keeps reacting on the pad and a late reading always comes out low.
Supplied in 4 presentations covering different measuring ranges. The range is chosen by model: 1, 500.