For water testing equipment to perform effectively, different solutions must be employed to aid the meter during storage or when in need of calibration. Storage solutions are used to prolong the service life of sensors by submerging them in a Potassium Chloride solution, not allowing the sensitive electrodes to dry out. Calibration solutions make sure that the readings you receive from your equipment are accurate, and are all rated differently depending on what meter you are calibrating. Different levels of calibration can also be applied based on your application of testing.