Proper Storage of a pH Electrode
By Hanna® Instruments and Carolina Biological Supply Company
Your pH electrode plays a very important role in measuring pH. It quantifies the ionic potential of a solution or, in other words, how much charge is moving within a solution. The pH meter then converts that data into a pH value. The electrode must be in proper working condition for the meter to give accurate readings.
The typical life of an electrode is 6 months to 2 years, depending on how often and in what application it is used. Specific factors that may affect the lifespan of your pH electrode are the temperature of samples, the composition of samples, and how the electrode is stored and maintained. Proper care and storage of pH probes not only ensures longer life but also more accurate readings.
Keep the pH electrode bulb moist at all times to minimize clogging and ensure fast response time. When not in use, keep the pH electrode bulb moist by pouring electrode storage solution in the cap (provided), then placing the cap over the bulb.
Electrode storage solution is inexpensive, and its use ensures that your electrode remains saturated during storage. Keep the cap on while the bulb is not in use. When storing the electrode for a long time, periodically check the cap to ensure the presence of storage solution and proper moisture of the bulb. If you do not have storage solution, you may use a pH 4 or pH 7 buffer solution as backup. If the pH electrode bulb dries out, soak it in a pH 7 buffer for a couple of hours (called “shocking” the electrode) before calibrating or taking measurements. Depending on how long the electrode was dry, it may be possible to restore the bulb’s ionic potential.
Remember, when measuring pH, the pH electrode plays a major role in getting accurate and reliable readings. While a number of outside factors may shorten the electrode’s life, you can lengthen its life and attain accurate readings with proper storage.