Using the PH-80 meter to measure the pH: Electrode Storage: Your PH-80’s sensor must be wetted in the electrode storage solution for at least 15 minutes prior to use. The solution is inside the large Mylar packet (included). Simply pour this solution into the cap, so that the sponge is moist. Excess solution can be poured out. Insert the meter into the cap and stand upright for 15 minutes.