pH Measurement and Correction of H2S for Waters

Refex (Europe) have designed their reference sensors for arduous applications particularly where fouling or poisoning conditions exist. The sensors use a highly stable non-porous polymeric interface in place of the traditional porous liquid junction used by other conventional reference electrodes.

With Refex reference sensors, the active reference area is the whole of the outside surface of the electrode; this super large contact area means that the electrode is supremely resistant to coatings.

One major problem with all pH/mV electrodes is the porous/leaking reference junctions rapidly failing. The main issue being the poisoning of the porous junction and KCl electrolyte. This happens by H2S back-diffusing through the porous junction. H2S reacts with the Ag/AgCl (silver/silver chloride) half cell and forms AgS - this precipitation occurs in the porous junction that destroys the mV stability. This degradation happens immediately after the electrode is installed and within a few days/weeks the electrode will be useless.

The Refex electrode is exceptionally resistant to applications containing poisons such as cyanide, ammonia and sulphides. This immunity is achieved because the polymeric reference is ionically conductive but not porous and prevents elements of the process from contaminating the electrode causing drift and inevitable failure.

The Refex electrode with the unique and patented Solid-State Non Porous Reference Retrofits to the Yokogawa flow cell and connects directly to the Yokogawa connecting cable. They are also compatible with Emerson cables, typically the 399 and 381 systems.

Refex electrodes often last 5-10 times longer than current electrodes and Refex are currently offering new customers a TRY-IT / BUY-IT free 90 day evaluation.