What is the difference between rechargeable and non rechargeable pH composite electrodes?
The pH composite electrode shell is distinguished between plastic and glass. A rechargeable pH composite electrode has a liquid adding hole on the electrode shell. When the external reference solution of the electrode is lost, the liquid adding hole can be opened to replenish the KCl solution. The non rechargeable pH composite electrode is filled with gel like KCl, which is not easy to drain and has no feeding hole.
The characteristic of a rechargeable pH composite electrode is that the reference solution has a high penetration rate, the liquid interface potential is stable and reproducible, and the measurement accuracy is high. Moreover, when the reference electrode is reduced or contaminated, KCl solution can be supplemented or replaced, but the disadvantage is that it is more troublesome to use. When using a rechargeable pH composite electrode, the filling hole should be opened to increase liquid pressure and accelerate electrode response.
When the dielectric liquid level is 2 centimeters lower than the filling hole, new dielectric liquid should be replenished in a timely manner.
The characteristic of non rechargeable pH composite electrodes is simple maintenance and convenient use, therefore, they have also been widely used. However, when used as a pH electrode in the laboratory, under long-term and continuous usage conditions, the concentration of KCl at the liquid interface will decrease, affecting the testing accuracy. Therefore, when non rechargeable pH composite electrodes are not used, they should be immersed in electrode immersion solution, so that the electrode performance will be good during the next test. However, some laboratory pH electrodes are not tested for long-term or continuous testing, so the impact of this structure on accuracy is relatively small. Industrial pH composite electrodes, due to their low requirements for testing accuracy, have become the main choice for ease of use.
