To prolong the life of the electrode, it should be immersed in a special solution when not in use. The solution is simply called, Storage Solution (HI 70300). The benefits are twofold. First, the glass will remain hydrated. This is very important as a dry electrode will degrade and must be rehydrated prior to use. Second, the salts in the solution are at the same concentration as the salts inside the electrode. Therefore no transportation of salts will occur to deplete the pH reference. Technically one could say that there is an absence of osmotic pressure across the junction. The life of an electrode will vary depending upon the type of solutions, temperatures, immersion times and cleaning cycles. Typically electrodes will last about a year although some can remain functional for two years. Rarely do electrodes exceed this life span. In some cases with severe conditions of use, electrode life may be as short as one month or even a few days! Selection of the proper electrode is important as hundreds of different types of probes are manufactured. Each probe is designed to accommodate different conditions of use to maximize its useful life.
