Analytical Instrumentation
Non-Porous Electrodes Solve the Most Common Causes of Failure
Jan 05 2016
Process plants require pH electrodes to be reliable, accurate and possessing of a good life expectancy, all things which can be reasonably expected of a quality pH sensor which is correctly calibrated, cleaned and undamaged.
When maintenance of electrodes is needed more often than should be necessary it can be an indicative of a problem. Common problems include: fouling/poisoning of the Ag/AgCl element or electrolyte (irreversibly wrecking the mV stability and integrity of the Ag/AgCl half-cell), coated or plugged diaphragms/junctions, and depleted internal electrolyte (KCl solution). All these issues affect the stability and accuracy of the electrodes, and ultimately cause failures which result in buckets filled with dead electrodes – losing hundreds of millions of dollars per year.
The Patented and Unique Refex (Ireland) electrode is the break-through that has solved all of these problems. Refex reference electrodes are Non-Porous - hence there is no contact or exchange of liquids between the process waters and the KCl electrolyte. Porous reference electrodes fail due to KCl electrolyte depletion/dilution across the porous junction into the process waters. This loss of electrolyte and dilution of the KCl causes mV drifting away from the electrodes Eo zero point. The mV integrity of the Refex reference, however, is guaranteed - it cannot be degraded and destroyed like all other porous reference electrodes.
The Refex non-porous reference interface, intended to eventually replace all porous reference electrodes, is a salt loaded ionically conducting polymer that doubles as an immobilised electrolyte - and more importantly as a protective interface/barrier that separates the chemically aggressive and often low ionic process waters from the electrodes internal KCl 2.8 mol/l electrolyte. Thus, it is impossible to poison or foul the Refex non-porous Ag/AgCl half-cell and KCl electrolyte, there are zero diffusion potential errors, and no electrolyte loss. In addition, Refex Non-Porous electrodes offer: no chemical precipitations with the Ag/AgCl half-cell, no problems with high and varying pressures up to 30 BAR from full vacuum, and no problems with high and varying temperatures (no blowing and sucking).
Refex Non-Porous electrodes are accurate, almost maintenance free, compatible with all good quality pH transmitters, and offer an instant response to pH change (very important for chemical corrections and titrations). Long electrode lives (many times longer than other brands) also mean huge savings for process plant operators.
Refex - The First to Last.
Digital Edition
PIN 25.5 Oct/Nov 2024
November 2024
Analytical Instrumentation - Picturing Viscosity – How Can a Viscometer or a Rheometer Benefit You? - Sustainable Grease Formulations: Evaluating Key Performance Parameters and Testing Method...
View all digital editions
Events
Dec 03 2024 Dusseldorf, Germany
Dec 08 2024 Anaheim, CA, USA
Turkey & Black Sea Oil and Gas
Dec 11 2024 Istanbul, Turkey
Dec 19 2024 Aurangabad, India
Jan 20 2025 San Diego, CA, USA