Restoring the Accuracy of a pH Electrode (for pH Meters)
When there is a significant measurement error in the pH electrode of our pH meter, we should know that some factors have begun to affect the pH electrode of the pH meter.
The "damage" of the pH meter composite pH electrode is caused by a decrease in sensitivity gradient, slow response, and poor reading repeatability, which may be caused by the following three factors. Generally, customers can use appropriate methods to repair it.
(1) If the electrode bubble and liquid interface are contaminated, a fine brush, cotton ball, or toothpick can be used to carefully remove the dirt. Some protective covers on the heads of plastic shell pH electrodes can be unscrewed for easier cleaning. If the pollution is severe, cleaning agents can be used according to the previous method.
(2) The external reference solution is contaminated. For rechargeable electrodes, a new KCl solution can be prepared and added. Note that it should be poured out again during the first and second additions to clean the electrode cavity.
(3) Aging of glass sensitive film: Soak the electrode bulb in 0.1mol/L dilute hydrochloric acid for 24 hours. Wash with pure water and soak in electrode soaking solution for 24 hours. If the passivation is severe, the lower end of the electrode can also be soaked in a 4% hydrofluoric acid solution for 3-5 seconds (solution preparation: 4ml hydrofluoric acid diluted to 100m1 with pure water), washed with pure water, and then soaked in the electrode soaking solution for 24 hours to restore its performance.
