Abstract: A solid state pH sensor having an indicator electrode of metal/metal oxide and a reference electrode of metal/metal salt applied to electrically conductive conductors, such as electrically conductive cermet conductors and electrically conductive metal pins, imbedded in an electrically non-conductive substrate, such as electrically non-conductive ceramic substrates including S-glass substrates. The sensing portion of the sensor preferably has a coating of an annealed perfluorocarbon copolymer. Alternatively, the indicator or reference electrodes may be formed on separate electrically non-conductive substrates with each having an electrically conductive conductor imbedded therein. These indicator or reference electrodes may be utilized with each other or with prior art indicator or reference electrodes.