Abstract: A system for obtaining a pH measurement comprises a disposable probe and a reusable reader. The disposable probe includes an indicating electrode and a reference electrode. The reader operably engages the disposable probe and provides pH information of a sample. The system is configured to be self-calibrating. The system is constructed and arranged to provide pH information based on the potentiometric measurement of the sample solution based on signals received from the at least one indicating electrode and the at least one reference electrode.