Introduction to restoring pH meter electrode accuracy
When there is a significant measurement error in the pH electrode of our pH meter, we should know that some factors have already 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. The humidity sensor probe, stainless steel electric heating tube, PT100 sensor, fluid solenoid valve, cast aluminum heater, and heating ring may be caused by the following three factors. Generally, customers can use appropriate methods to repair them.
(1) The electrode bubble and liquid interface are contaminated, and a fine brush, cotton ball, or toothpick can be used to carefully remove the dirt. The protective cover on the head of some 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, paying attention to safety. When adding it again, it should be poured out 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 the electrode in a solution for 24 hours. If the passivation is severe, the lower end of the electrode can also be immersed in a 4% hydrofluoric acid solution for 3-5 seconds (solution preparation: 4ml of hydrofluoric acid diluted to 100ml with pure water), washed with pure water, and then immersed in the electrode immersion solution for 24 hours to restore its performance.
