Macherey-Nagel test strips for chlorine dioxide where free chlorine is also present, in one presentation.
91362
A semi-quantitative test strip for chlorine dioxide where free chlorine is also present. Dip it, wait the stated time, and compare the pad against the colour scale on the tube.
Most chlorine dioxide tests cannot tell the two oxidants apart, so a system dosing both gives a reading that is neither. The DK version is formulated to separate them, which is what makes it useful in a real plant rather than in a clean sample.
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.
Follow the sequence in the instructions exactly; the discrimination between the two oxidants depends on it.
Supplied in one presentation.