| 摘要 |
PURPOSE:To enable accurate measurement of several % or below of the absolute humidity by using a solid electrolyte having hydrogen ion conductivity and oxygen ion conductivity in combination and making selective use of only the oxygen ion conductivity. CONSTITUTION:Porous platinum electrodes are provided on both faces of the solid electrolyte 1 consisting of perovskite type oxide such as; for example, BaCeO3, having hydrogen ion conductivity and oxygen ion conductivity of both 1 hydrogen ion transference number and oxygen ion transference number in combination. One of said electrodes is used as an anode and the other as a cathode 3. A cap 5 formed with a microhole 4 is joined as a gas diffusion control layer to the solid electrolyte 1 to cover the anode 2. A DC voltage is impressed between the anode 2 and the cathode 3 in the gas to be measured. Decomposition of H2O in the anode 2 is suppressed by the microhole 4 and since the generation of a hydrogen ion H<+> is negligible, the absolute humidity is detectable from the limiting current an which the output current with the oxygen ion O<2-> generated by electrolysis on the cathode 3 as a carrier is satd. |
