| 摘要 |
PURPOSE:To remove the pressure dependence of sensor output by preventing a diaphragm from generating deformation, by providing a space part in the container of a galvanic battery type oxygen sensor and forming one wall of the space part as a perforated one to hold to exterior and interior thereof to same pressure. CONSTITUTION:A space part 7 is provided to the upper part of a galvanic battery type oxygen sensor, wherein an anode 1 formed by plating a Ti-plate with gold, a cathode 2 made of lead, an electrolyte 3 comprising an aqueous solution of a mixture of propionic acid and a potassium salt thereof and a container 4 made of ABS are provided and an unperforated diaphragm 5 made of a tetrafluoroethylene/hexafluoroethylene copolymer is adhered to the container 4, and a porous polytetrafluoroethylene membrane 6 is adhered to the upper wall of the space part 7. By providing the membrane 6, the pressure in the sensor changes corresponding to the change in external pressure to prevent the deformation of the diaphragm 5. When the steam pressure in an atmosphere became higher than that of the electrolyte, the internal pressure of said sensor does not rise even if the electrolyte absorbs moisture and the amount thereof increases. In the contrary case, the open air enters even if moisture in the electrolyte is evaporated and the reduction in internal pressure is avoided. By this mechanism, the pressure dependence of the sensor is removed. |
