| abstract |
A gas sensor includes a multi-layered solid-state pH electrode and a reference electrode coated with a gas-sensitive layer (solid-state or gel-state) sensitive to an ion of interest, the surface of the combination being coated with a gas-permable layer. Also provided in a gas sensor having a pH electrode and a reference electrode immersed in a gas-sensitive solution within a gas-permeable layer. Preferably, a fixed distance is maintained between a sensitive portion of the pH electrode, a sensitive portion of the reference electrode and the gas-permeable layer isolated by means of a porous layer. In another emodiment, the gas sensor incorporates a common electrode and a thermister for temperature calibration. |