pH / ORP Electrode

LibertyCES has documented pH / ORP Electrode specified across 1 sector application, including Aquatics / Aquariums / Water Parks / Zoos / Swimming Pools.

ProMinent names pool water and aquariums as the typical application for five distinct sensor types; the plastic-shaft PHEK/RHEK variants exist specifically for aquatic installs. Real detail: RHES Au uses gold electrodes because gold resists the hydrogen susceptibility that degrades platinum in pool water. — examples include ProMinent DULCOTEST PHES (drinking/pool water, 1-12 pH, 60°C/3 bar, 1x ceramic), PHEK (pool + aquariums, plastic shaft), RHES Pt and RHES Au, RHEK Pt (pool + aquariums, plastic shaft), RHEKL Pt (2x ceramic, horizontal install). This is well-documented in LibertyCES's field data.

The actionable rule from Signet's own Application Matrix: a customer measuring pH or ORP in a stream containing mercury, copper, lead, cyanide, sulfide or silver-complexing chemicals should be quoted the 2764-2767 Harsh Chemicals family (rated ***** Better), not the general-purpose 2724-2726 or 2734-2736 families (rated only ** Compatible). Both technically work — the difference is electrode life in that chemistry, which is the entire economics of a plating-line pH loop. Use 2774-2777 as the cheaper middle tier when only copper/lead/mercury are present. Separate hard finding: every family rates HF <2% as either Ø or ***** with no middle ground, so HF service requires the dedicated HF glass variant. ProMinent confirms independently with PHED, whose stated application is electroplating contaminated with Cr6+ and CN-. Also the direct link to photographic solutions — the silver-halide and silver-cyanide poisoning columns are exactly photographic fixer chemistry. Signet's calibration guidance separately names strong NaOH, KOH and HF as pH-glass eroding agents. Materials to confirm: Ryton (PPS) electrode body, PTFE reference junction (2734-2736) vs UHMWPE (2724-2726) vs differential isolated chamber (2764-2767), HDPE diaphragm (ProMinent PHEF, fluoride service), HF-resistant glass variants (2724-HF/2726-HF/2734-HF/2736-HF), Signet rating scale: Ø Not Recommended, ** Compatible, *** Good, ***** Better. Specific chemicals include hexavalent chromium (Cr6+), cyanide (CN-), sulfide (S2-), mercury (Hg2+), copper (Cu+/Cu2+), lead (Pb2+), perchlorate (ClO4-), bromide (Br-), iodide (I-), silver sulfide (Ag2S), silver bromide (AgBr), silver iodide (AgI), silver cyanide (AgCN), hydrofluoric acid <2%, fluoride etching solutions.