Solve the problem of small electrode of PH meter
What are the materials of electrode? Generally, there are two kinds of pH electrode casings: PC plastic (polycarbonate) casing and glass casing. The PC casing is resistant to collision and impact, but the applicable temperature is less than 80oC. And it is easy to corrode in high alkaline solution and some media. The applicable temperature of glass shell is 0-150oC, and it is generally not corroded except hydrofluoric acid solution, but it is easy to be damaged by collision. Stainless steel, PTFE, metal, etc.
What are the different uses of different materials of electrodes? Pc plastic, polycarbonate, PC shell is resistant to collision and impact, but it is suitable for PTFE electrode with temperature less than 80oC, which is commonly known as plastic king, except for some organic solvents. Glass electrode can resist high temperature and corrosion (except hydrofluoric acid) and is easy to break. If the medium with HF and no corrosiveness is at 0-100 degrees Celsius, stainless steel electrode can be used; If the medium contains organic solvent, PTFE electrode can be used, which can resist high temperature, about 280 degrees Celsius; PH electrode * The high temperature can reach 130 degrees Celsius, and the imported electrode is recommended for those higher than 130 degrees Celsius.
3 How long is the life of the electrode in normal use?
Generally, the electrodes are used for six months to one year, depending on the working conditions, and some are used for one and a half to two years. Imported products may last for 3-5 years, but the price is expensive!
4. How to protect the electrode? (1) The glass film at the lower end of the glass electrode is easily broken, and it is forbidden to contact with hard objects. (2) When it is used for the first time, part of the spherical glass membrane should be soaked in distilled water day and night. It should also be soaked in distilled water when not in use, so that the soaking procedure can be simplified next time. (3) When measuring the strongly alkaline solution, it should be operated as soon as possible, and washed with water immediately after the measurement, so as to avoid the alkali solution from corroding the glass film. (4) The glass film shall not be stained with oil. If this happens, Gangfu is first immersed in distiller's grains, then put into ether or carbon tetrachloride, then moved into alcohol, and finally washed with water and immersed in human water. (5) The plexiglass tube on the electrode plug has excellent insulation performance, and it is forbidden to contact with chemicals or oil stains.
5. What should I do if I don't use the electrode for a long time? Storage and cleaning of glass electrode of ph meter: short term: storage in buffer solution with pH = 4; Long term: stored in buffer solution with pH = 7. Contamination of glass electrode bulb may prolong the electrode response time. You can wipe off the dirt with CCl4 or soap solution, and then immerse it in distilled water for one night and then continue to use it. When the pollution is serious, it can be soaked in 5% HF solution for 10 ~ 20 minutes, washed with water immediately, and then immersed in 0.1NHCl solution for one day and night before continuing to use.
6. What is the difference between the life and price of domestic electrodes and those of imported electrodes? The service life of domestic electrodes is not as long as that of imported electrodes. Under normal circumstances, it can be used for about 2-3 years, while domestic electrodes can be used for 1-1.5 years under normal circumstances, except in special circumstances. But the price of domestic electrodes is cheaper than that of imported electrodes.
