A smart sensor system is provided which uses a monitoring electrode to produce a calibration output that can be used in-situ and in real-time to monitor and address reference electrode drift and to provide information regarding sensor operation. The monitoring electrode uses a redox chemistry that is either a non-active redox species that is not sensitive to changes in a solution being tested/monitored or a redox active species that sets a pH of the local environment proximal to the electrode when the electrode is contacted with a test and/or reference solution. The smart sensor system includes at least one of a solid-state electrochemical sensor; a glass electrode, a reduction oxidation sensor; and/or a glucose sensor and/or a sensor to monitor constituent parts of the solution composition.