Macherey-Nagel test strips for arsenic, in 3 presentations covering different measuring ranges.
91334
91345
91332
A semi-quantitative test strip for arsenic, a naturally occurring contaminant of groundwater. Dip it, wait the stated time, and compare the pad against the colour scale on the tube.
Arsenic is invisible, tasteless and cumulative. It comes from the rock the well passes through rather than from any spill, so a clean-looking well in a clean-looking area can still be unsafe, and only a test will say so.
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.
A field screen is for finding wells that need attention, not for certifying one as safe. Confirm any positive in a laboratory.
Supplied in 3 presentations covering different measuring ranges. The range is chosen by model: 10, 50.