Patent ID: 7758736
Filing Date: 2010-07-20
Classification: G01N

Abstract:
1. A gas sensor comprising: a detecting element which extends in an axial direction and has a detecting portion at a front end portion thereof, the detecting portion detecting a specific gas component contained in a gas-to-be-measured; a housing which holds and radially encloses the detecting element, the detecting portion of the detecting element projecting from a front end portion of the housing; an inner protector which has a circumferential wall, said inner protector having a front end wall located on a front side of the circumferential wall, and a rear, open end portion fixed to a front end portion of the housing so as to accommodate the detecting portion of the detecting element in the inner protector, and which inner protector has an inner introduction hole formed in its circumferential wall for introducing the gas-to-be-measured into the inner protector; and an outer protector which assumes a cylindrical shape enclosing the circumferential wall of the inner protector, such that a clearance is present between the inner protector and the outer protector, and which outer protector has an outer introduction hole formed in a circumferential wall of the outer protector for introducing the gas-to-be-measured into the clearance; wherein at least either the inner protector or the outer protector has a taper portion formed on a front end side of its circumferential wall and reducing frontward in outside diameter, and the front end wall of the inner protector includes a recess portion having: