Macherey-Nagel test strips for dissolved aluminium, in one presentation.
91307
A semi-quantitative test strip for dissolved aluminium. Dip it, wait the stated time, and compare the pad against the colour scale on the tube.
Aluminium salts are dosed as coagulants in water treatment, and what should happen is that they settle out. Aluminium still dissolved in the finished water means the coagulation step is being run wrong — wrong dose or wrong pH.
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.
Aluminium solubility is strongly pH dependent and is at a minimum near neutral; a high reading is often a pH problem rather than a dosing one.
Supplied in one presentation.