Patent ID: 7607340
Filing Date: 2009-10-27
Classification: G01N

Abstract:
1. A gas sensor comprising: a detecting element having a detecting portion provided at a front end portion of the detecting element and adapted to detect a specific gas component contained in a gas-to-be-measured; a housing radially enclosing the detecting element, the detecting portion of the detecting element projecting from a front end of the housing; an inner protector having a rear end portion fixed to a front end portion of the housing and accommodating the detecting portion, said inner protector having a plurality of inner introduction holes for introducing the gas-to-be-measured into the interior of the inner protector, the inner introduction holes being formed in a circumferential wall of the inner protector along a circumferential direction and located rearward of a front end of the detecting element; and a cylindrical outer protector radially enclosing the inner protector such that a clearance is present between the inner protector and the outer protector, the outer protector having a rear end portion fixed to the front end portion of the housing and a plurality of outer introduction holes for introducing the gas-to-be-measured into the clearance, the outer introduction holes being formed in a circumferential wall of the outer protector along a circumferential direction and located frontward of the inner introduction holes of the inner protector with respect to an axial direction of the gas sensor, wherein the inner introduction holes individually have an opening area of 3.5 mm wherein the circumferential wall of the inner protector has a taper portion whose diameter radially reduces toward a front end of the inner protector and the inner introduction holes are formed in the taper portion, and wherein the inner protector has a tubular portion continuous with a front end of the taper portion, and the detecting element has a gas introduction portion for introducing the gas-to-be-measured into the interior of the detecting portion and the gas introduction portion is disposed such that the gas introduction portion faces, in a crossing manner, a boundary between the taper portion and the tubular portion.