Macherey-Nagel
On demand
Macherey-Nagel test strips for silver accumulated in a photographic or radiographic fixing bath, in one presentation.
90741
A semi-quantitative test strip for silver accumulated in a photographic or radiographic fixing bath. Dip it, wait the stated time, and compare the pad against the colour scale on the tube.
A fixing bath fails when it is saturated with silver, and the images it produces then fade over years rather than immediately — the damage is discovered long after the bath was replaced. The bath is also worth money as silver, and worth a fine if it reaches a drain.
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.
Test the bath, not the rinse; the useful decision is when to send the fixer for recovery.
Supplied in one presentation.