| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a gas sensor, having a small hysteresis even in exhaust gas atmosphere of extremely low concentration in ppm order and capable of preventing crack generation due to thermal shock. <P>SOLUTION: The gas sensor, which detects a concentration of an objective gas based on electromotive force depending on the concentration of the objective gas within a measured gas, comprises an oxygen conductive solid electrolyte, a reference electrode formed on one surface of the solid electrolyte, a detection electrode facing the reference electrode and formed on another surface of the solid electrolyte, and a heating means for heating the solid electrolyte; the solid electrolyte has a gradient microstructure in which the crystal particle size of the solid electrolyte gradually comes to finer from the reference electrode toward the detection electrode. The solid electrolyte may be a laminate having a plurality of sintered electrolyte layers with different crystal particle sizes; in this case, the sintered electrolyte layer adjacent to the detection electrode contains 5 to 50 vol% of palladium based on 100 vol% of the electrolyte. <P>COPYRIGHT: (C)2009,JPO&INPIT |
