Traditional pH and ORP sensors with porous/open reference junctions used in processes involving aggressive and toxic chemicals often fail due to reference electrode poisoning. Chemicals in the process diffuse through the built-in porous/open junction(s) necessary for this type of sensor to operate and poison the Ag/AgCl electrode within the reference half-cell. Reference electrode poisoning leads to serious measurement performance problems and premature sensor failure. Besides the high cost of frequent replacements, there is also the cost of safely [and legally] handling and disposing of potentially highly contaminated sensors. Improper disposal of contaminated sensors can have a significant environmental impact and expose companies to additional costs through lawsuits and penalties.
The obvious solution to this challenging environmental problem is the use of Refex Non-Porous pH and ORP sensors. All Refex sensors use a reference cell without a porous junction, thus preventing the ingress of hazardous materials such as chemicals, biological agents, and radioactive materials. Instead of a porous junction, Refex sensors use a patented ionic conductive interface barrier to connect the process to the reference electrode. This barrier prevents all contact between the process fluid and the reference half-cell electrolyte. There is no risk of internal contamination of the Refex sensor with any hazardous substances. Refex pH and ORP sensors can be safely used in challenging applications, such as those involving toxic chemicals, biological agents, or radioactive materials, without the additional worry and cost of safe disposal after they are depleted. In addition (and unlike many conventional sensors), they offer reliable, drift-free measurement and an exceptionally long lifespan.
Typical contaminants include:
Cadmium Peroxide Active Biologics Cyanide Ammonia Strong Acids
Chlorine Hydrogen Sulfide Strong Alkalies Chromium Radioactive Materials Many, many more…
