Macherey-Nagel
On demand
Macherey-Nagel test strips for molybdate, in one presentation.
91325
A semi-quantitative test strip for molybdate, dosed as a corrosion inhibitor. Dip it, wait the stated time, and compare the pad against the colour scale on the tube.
Molybdate replaced chromate in closed cooling and heating loops because it protects steel without the toxicity. It only works above a threshold concentration, so a loop dosed at half strength is not half protected — it is unprotected.
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.
Molybdate is also used as a tracer to detect dilution: a falling reading with no dosing change means the loop is leaking.
Supplied in one presentation.