| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a gas sensor element capable of preventing a crack caused by freezing of water permeated into a porosity protective layer when forming the porous protective layer into a plurality of layers, and to provide a gas sensor using the gas sensor element. <P>SOLUTION: A gas sensor element 100 comprises: a laminate formed by laminating a detection element part 300 having solid electrolytes 105 and 109 and a pair of electrodes 104, 106 and a pair of electrodes 108, 110 disposed at the solid electrolytes respectively, and a heater part 200, and having an approximately rectangular cross section in a direction intersecting perpendicularly with a longitudinal direction; and a porous protective layer 20 formed by covering the entire circumference of a tip part exposed to a measuring object gas in the laminate. The porous protective layer includes an inner side porous layer 21 provided on the side of the detection element, and an outer side porous layer 23 formed on the inner side porous layer. The porosity of the inner side porous layer is higher than that of the outer porous layer, and also a difference of porosities of four portions in the inner side porous layer positioned on two short sides and two long sides of the laminate in a cross section is 10% or less. <P>COPYRIGHT: (C)2012,JPO&INPIT |
