Introduction to How to Repair a pH Electrode
The "damage" of pH composite electrodes is characterized by a decrease in sensitivity gradient, slow response, and poor repeatability of readings, which may be caused by the following three factors. Generally, customers can use appropriate methods to repair it.
If the electrode bubble and liquid interface are contaminated, a fine brush, cotton, or toothpick can be used to carefully remove the dirt. Some protective covers on the heads of plastic shell electrodes can be unscrewed for easy cleaning. If the pollution is severe, it can be cleaned with a cleaning agent according to the method in Article 8.
The external reference solution is contaminated, and some electrode structures can add solutions. At this time, a syringe can be used to remove the external reference solution of the electrode, prepare a new 3.3mol/L or saturated KCl solution, and add it again. Note that the first and second additions should be taken out again to clean the electrode cavity.
Aging of glass sensitive film: Soak the electrode ball in 0.1mol/L dilute hydrochloric acid (9mL hydrochloric acid diluted with pure water to 100mL) for 24 hours, rinse with pure water, and then soak in the electrode soaking solution for 24 hours. If the passivation is severe, the lower end of the electrode can also be soaked in a 45% hydrofluoric acid solution for 3-5 seconds (solution preparation: 4 mL hydrofluoric acid diluted with pure water to 100 mL), washed with pure water, and then soaked in the electrode soaking solution for 24 hours to restore its performance.
