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Maintenance

FAQ | Maintenance
Questions Answers
The KCl solution in the electrode has been partially crystalized: does the entire reference electrolyte need to be replaced or can 3 mol KCl solution be added? What happens if the concentration of the KCl solution in the electrode is no longer exactly 3 mol/l? Procedure: Completely remove the electrolyte, add water and dissolve the KCl crystals. After that, remove the solution and add some 3 M KCl (in order to remove possibly adhering solution inside the electrode) and then remove. Then, fill up with 3 M KCl. Differences in the concentration of the electrolyte solution lead to differences in the measured potential and therefore influence the measured ph value.
What do I do if an electrode is dried out? Dissolve possible KCl crystals in water, fill in new electrolyte solution and hydrate for 24 hours in 3 M KCl. After this treatment, a calibration must be performed to decide whether the electrode is still usable.
How do I keep or store the electrode properly? With liquid gel electrodes (one-rod measuring chains and reference electrodes), the respective electrolyte solution should be filled into the hydration cap. For gel electrodes, a 3 mol/l KCl solution is sufficient. For individual glass electrodes, fill de-ionized water.
What is the best way to clean the electrode? "Contamination on membrane and diaphragm result in measurement deviations. Calcareous depositions can be removed with thinned mineral acids (e.g. diluted hydrochloric acid), organic contamination can be dissolved with suitable solvents, fats can be removed with surfactant solutions, and protein can be dissolved with pepsin solution (e.g. cleaning solution L510). General tips – Rinse the electrode with distilled water after the measurement and the cleaning, do not rub dray and do not use as a stirrer. – To refill and store the electrode, see question ""How do I keep or store the electrode?"". – Extreme pH values and temperatures shorten the life time and limit the accuracy of the electrode. – Hydrofluoric acid, hot phosphoric acid and strong alkalines destroy the ph glass membrane. "
How long and where can I store electrodes? An electrode ages, even if it is not used, therefore it should not be stored for extended periods of time.