MACHEREY-NAGEL Special Indicator Paper

Indicator paper on a reel, cut to whatever length the job needs. Where a strip is one test, a reel is a few hundred — which is what makes it the economical format anywhere pH gets checked many times a day rather than occasionally.

Narrow ranges, and why they matter

These are special ranges rather than universal ones: each reel spans two to four pH units instead of the whole scale. A paper covering 5.4–7.0 resolves within that window far more finely than a 1–14 paper ever can, because the same set of distinguishable colours is spread over a fraction of the range.

That is the difference between knowing a rinse is around neutral and knowing it is 6.4 rather than 7.0 — which in a process with a specification is the difference between passing and failing.

Eleven ranges are stocked, from pH 0.5–5.5 at the acid end through to 12.0–14.0 at the alkaline end, with overlapping windows so any point on the scale can be resolved by one of them.

Reels and refills

Each range is sold as a reel in its own dispenser, and again as a refill pack for that dispenser. Buy the dispenser once and refills after — the dispenser holds the colour chart alongside the paper, and a reel separated from its chart is the most common cause of a misread.

One range is supplied as a boxed TRI set containing three test papers rather than as a reel.