Do any of your sensors require special storage?

Yes, there are a few sensors that need to be stored properly in order to stay in good condition.

Oxygen Gas Sensors should be stored upright. This is easily done by storing them in the bottle in which they were shipped.

Dissolved Oxygen Probes should have the filling solution emptied and rinsed out, then stored dry.

pH Sensors should be stored in the storage solution provided and in a vertical position. Replacement solution can be made (10 grams KCl in 100 mL pH 4 buffer solution) or purchased (order code PH-SS, 500 mL).
     TIL 369: Where do I get pH Storage Solution? (Buffer Storage Solution)

ORP (Oxidation-Reduction Potential) sensors should be stored in the storage solution provided. Replacement solution can be made (10 grams KCl in 100 mL pH 4 buffer solution) or purchased (order code PH-SS, 500 mL).

Ion Selective Electrodes should be stored in the humid environment of the storage bottles in which they are shipped. If the sponge at the bottom of the storage bottle dries out, simply add a few drops of distilled water.