| 摘要 |
PURPOSE:To make the limiting current characteristic sharp by employing a ceramic filter with a specified porosity and average pore size for the gas diffused resistance layer of a limiting current type oxygen concentration detector. CONSTITUTION:A solid electrolytic element 1 is made up of a sintered body of an oxygen ion conductive metal produced, for example, by solid solution of 92mol% of ZrO2 and 8mol% of Yb2O3 and is shaped like a cup with one end thereof closed while with the other end thereof opened. A thin-film-shaped porous electrode is provided roughly on the entire inner surface of the element 1 while another thin-film-shaped porous electrode 3 is provided on the outer surface of the tip thereof. A gas (oxygen molecule) diffused resistance layer 6 made of a porous electrically insulating metal oxide is mounted on the outside of the electrode 3. This gas diffused resistance layer 6 shall be a continuously porous ceramic filter which is 5-11% in the porosity, 500-1,000Angstrom in the average pore size, 250-1,200Angstrom in the pore distribution and 200-1,000mum in the thickness. |
