Replacement pH/ORP sensor is user-replaceable and features a unique/porous liquid-junction.

The pH/ORP sensor in the Myron L Ultrameter must be maintained with an electrode strorage solution whenever it is in storage or not being used. An electrode storage solution will keep your probe hydrated and protect the electrolyte embeded inside the probe. If the probe becomes de-hydrated it will most like fail and need to be replaced by the RPR replacement probe.