This is a solution that can be used to store your pH electrode. To ensure an optimum response time, the glass sensor tip and the reference junction of the pH electrode should be kept moist and not be allowed to dry out when not in use. Placing the electrode in a small glass filled with storage solution or replacing the solution in the protective cap is a suitable way to store the electrode. The solution should also be used to rehydrate the electrode after a cleaning procedure by soaking for at least one hour before taking measurements.
Note: never store pH or ORP electrodes in distilled or deionised water. Doing so will shorten the life of the sensor.
Hanna storage solutions are specially formulated to have an expiration of 5 years from manufacture for an unopened bottle.
From: Hanna Instruments