Do you know that the electrode of the online pH meter is damaged and how to repair it?
In the process of ph measurement, the most influential factor is temperature. At different temperatures, even the same water sample will have different ph values. Therefore, various online ph meters are equipped with temperature compensation circuits to eliminate this effect. When calibrating, use the resistance box to input a specific resistance, and input the corresponding temperature value. The instrument will establish the functional relationship between temperature and resistance base, then when measuring, the resistance value transmitted from the temperature electrode can be calculated to obtain the temperature value. The quality of the electrode of the online ph meter is the key that directly affects the test results.
The "damage" of the composite electrode of the online pH meter mainly refers to the decrease in sensitivity gradient, slow response, and poor reading repeatability. Generally, customers can use appropriate methods to repair it. The following is a detailed introduction to the "damage" reasons and repair methods of the online ph meter.
1. The electrode bulb and liquid junction of the online pH meter are polluted, and the dirt can be carefully removed with a fine brush, cotton ball or toothpick. The protective cover of the electrode head of some plastic shell pH meters can be unscrewed, which makes cleaning more convenient. If the pollution is serious, it can be cleaned with detergent.
2. The external reference solution is polluted, and some electrode structures can be added to the solution. At this time, the external reference solution of the industrial online pH meter electrode can be pumped out with a syringe to prepare a new 3.3M or saturated KCl solution. Add it again, pay attention to di yi, 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 glass sensitive film: Soak the electrode bulb of the industrial online pH meter with 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 with the electrode soaking solution of the pH meter for 24 hours . If the passivation is serious, you can also soak the lower end of the electrode of the industrial online pH meter in 4% hydrofluoric acid solution for 3-5 seconds (solution preparation: 4ml hydrofluoric acid is diluted to 100ml with pure water), and then washed with pure water , and then soak in the pH meter electrode soaking solution for 24 hours to restore its performance.
