How to restore the accuracy of the pH electrode of the pH meter
When the ph electrode of our PH meter has a large measurement error, we should know that some factors have begun to affect the ph electrode of the PH meter.
The "damage" of the composite ph electrode of the PH meter, the phenomenon is that the sensitivity gradient is reduced, the response is slow, and the reading repeatability 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 ball or toothpick. The protective cover on the head of some plastic shell pH electrodes can be unscrewed, which makes cleaning more convenient. If the pollution is serious, you can use detergent to clean it according to the previous method.
(2) The external reference solution is polluted. For the rechargeable electrode, you can prepare a new KCl solution and add it. Note that it must be poured out when adding it for the first and second time, so as to clean the inner cavity of the electrode.
(3) Aging of the glass sensitive film: Soak the electrode bulb with 0.1mol/L dilute hydrochloric acid for 24 hours. Rinse with pure water, then soak in electrode soaking solution for 24 hours. If the passivation is serious, you can also soak the lower end of the electrode in 4% hydrofluoric acid solution for 3 to 5 seconds (solution preparation: 4ml hydrofluoric acid diluted with pure water to 100m1), wash it with pure water, and then put it on the electrode. Soak in the soaking solution for 24 hours to restore its properties.
