How to repair pH electrode?
The "damage" of the pH composite electrode, the phenomenon is that the sensitivity gradient is reduced, the response is slow, and the repeatability of the reading is poor. It may be caused by the following three factors. Generally, customers can use appropriate methods to repair it:
(1) The electrode bulb and liquid junction are contaminated, and the dirt can be carefully removed with a fine brush, cotton or toothpick. The protective cover of some plastic shell electrode heads can be unscrewed, which is convenient for cleaning. If the pollution is serious, it can be cleaned with detergent according to the method in Article 8.
(2) The external reference solution is contaminated, and some electrode structures can be added to the solution. At this time, the external reference solution of the electrode can be pumped out with a syringe, and a new 3.3mol/L or saturated KCl solution is prepared, and then added Go in, pay attention to first, and then pull it out when adding it for the second time, so as to clean the inner cavity of the electrode.
(3) Aging of the glass sensitive film: Soak the electrode bulb in 0.1mol/L dilute hydrochloric acid (9mL hydrochloric acid diluted to 100mL with pure water) for 24 hours, wash it with pure water, and then soak it in the electrode soaking solution for 24 hours. If the passivation is serious, you can also soak the lower end of the electrode in 45 hydrofluoric acid solution for 3 to 5 seconds (solution preparation: 4mL hydrofluoric acid diluted with pure water to 100mL), wash it with pure water, and then, Soak the electrode in the soaking solution for 24 hours to restore its performance.
