<p>A differential pH probe (150) design uses a container (100) having an outer surface and an inner volume, where the inner volume is divided into a first chamber and a second chamber. A first pH-sensitive area (101) is located on the outer surface of the first chamber where the first pH-sensitive area (101) is configured to be exposed to a sample. A second pH-sensitive area (103) is located on the outer surface of the second chamber where the second pH-sensitive area (103) is shielded from the sample and is exposed to a buffer solution. A first electrode (111) is configured to detect a first voltage in the first chamber and a second electrode (112) is configured to detect a second voltage in the second chamber. Circuitry (110) is coupled to the first and second electrodes (111) and (112) and configured to process the first voltage and the second voltage to determine a pH of the sample.</p>
