GF Signet 4632 Chlorine Dioxide Analyzer System - Manual (Page 38)

38 463X Chlorine System Manual
Electrode Care and Application
pH electrodes are similar to batteries; they age with time and usage. The following information will help maximize electrode life.
General Tips:
• To ensure uninterrupted operation of critical pH systems, replacement electrodes should be available.
• Store boxed electrodes À at or upright (electrode tip down) to maximize hydration of the glass surface.
• Keep the glass surface wet at all times.
• Soak the sensor tip in pH 4.0 buffer during system maintenance intervals.
• If the sensor dehydrates, soak the sensor tip in pH 4 buffer for 24 to 48 hours, then visually inspect the electrode for surface
cracks, swelling, or discoloration.
• It may not be possible to restore severely dehydrated electrodes to normal operation.
• High temperatures, strong acids or caustics will increase electrochemical reactions and speed electrode aging.
• Coatings (e.g. grease) on the glass or junction surfaces cause extended response time and inaccurate measurement.
• Never store the electrode tip in deionized (DI) water. Use pH 4 buffer solution to keep the glass wet when out of the process.
• Never store the electrode at temperatures below 0 °C (32 °F) or allow it to dehydrate.
• Never scrape or sand the glass electrode surface.
• Treat glass electrode surfaces with care to prevent accidental breakage.
Maintenance - 2724 DryLoc ® pH Electrode
Problem Suggested Solution
Hard Coatings
Use a dilute acid solution (HCl solution of 5% or less). If the electrode has been used in applications
with a pH value higher than 7 pH, soak the electrode for 2 to 5 minutes.
Use a dilute alkaline solution (NaOH solution at 5% or less) if the electrode has been used in
applications with pH values less than 7 pH, soak the electrode for 2 to 5 minutes.
Alternating immersion in acidic and alkaline solutions may be necessary for thorough cleaning.
Soft Coatings
Spray or vigorously stir the electrode with a mild detergent, such as dishwashing liquid. Chlorine
bleach can also be used.
Oily or Organic Coatings
Spray or vigorously stir the electrode with a mild detergent or an appropriate solvent that will not
attack the materials of construction (isopropyl alcohol or similar).
After Cleaning
Always rinse the electrode with water after cleaning.
Soak the electrode in a pH 4 buffer (with KCl if available) for at least 10 minutes after cleaning.
Cleaning
Appendix