What is the correct way to store pH electrodes?

Proper storage of your pH probes can greatly extend the life of your probes, saving you time, energy and money. Here are some key points on how to get the most out of your probes.

First of all, you should make sure to keep the pH electrode wet at all times, a good solution for immersing the probe in water for long and short term storage is 4M Potassium Chloride solution (KCl). Revert to pH 4 or 7 buffered solutions when potassium chloride solution is not available. Potassium chloride solution (also known as pH storage solution or electrode storage solution) is available from most laboratory suppliers including Westlab (click here to view the product).

Also remember: Do not store pH electrodes in distilled or deionized water, as this will have few ions present and will cause ions to leach out of the glass bulb and render the electrode useless.

After storage, you may notice white potassium chloride crystals forming on the exterior of the electrode. This is normal and will not interfere with the measurement. If this happens, gently wash the electrode with tap water and dry it before use, being careful not to put pressure on the electrode

Most electrodes are shipped with a protective cover over the glass bulb to prevent damage in transit. Before using the electrodes, remove the rubber caps. Wear the cover to store the electrode for long periods of time, filling the cover with only enough 4M potassium chloride solution to cover the glass bulb, and topping up frequently to keep the bulb moist. Alternatively, dip a small sponge into the storage solution and insert into the cap. This will provide extra protection to the bulb and retain moisture for a longer period of time.