Macherey-Nagel test strips for sulfate, in one presentation.
91329
A semi-quantitative test strip for sulfate. Dip it, wait the stated time, and compare the pad against the colour scale on the tube.
Sulfate is what makes concrete deteriorate in aggressive ground, what feeds the bacteria that turn a sewer to hydrogen sulfide, and what forms the scale that reverse osmosis membranes cannot be cleaned of.
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.
Sulfate scale is the one that does not dissolve in acid; on a membrane it is prevented, never cured.
Supplied in one presentation.