The rechargeable pH composite electrode has a liquid hole on the shell of the electrode. When the external reference solution of the electrode is lost, the liquid hole can be opened and the KCl solution is resupplemented. The gel like KCl in the non rechargeable pH composite electrode is not easy to lose and no liquid hole is added.

The characteristics of filled pH composite electrode is higher than the penetration rate of reference solution, the liquid junction potential stable return, high precision. But when the ratio of electrode to reduce or contaminated can supplement or replace the KCl solution, but the disadvantage is the use of more trouble. Rechargeable pH composite electrode used when the liquid filling hole is opened, to increase the fluid pressure, accelerating electrode response, while the ratio of liquid level is below the liquid adding hole 50px, should be added a new reference solution.

The characteristic of non rechargeable pH composite electrode is easy to use and easy to use, so it is also widely used. But as the use of laboratory pH electrode, in the long-term and continuous use conditions, the concentration of KCl at the liquid junction will decrease, affect the test accuracy. Therefore, the non rechargeable pH composite electrode should be immersed in the immersion solution when it is not used. So the performance of the electrode will be very good next time. Most pH electrodes in laboratory are not long-term and continuous tests, so the effect of this structure on the accuracy is relatively small. The industrial pH composite electrode has a low requirement for testing precision, so it is the main choice to use it easily.