Patent ID: 7827849
Filing Date: 2010-11-09
Classification: G01N

Abstract:
1. A gas sensor comprising: a detecting element, extending in an axial direction of the gas sensor, and having a detecting portion which is provided at a front end portion of the detecting element and adapted to detect a gas component contained in a gas-to-be-measured; a housing which encloses the detection element therein with the detection portion of the detection element projecting from a front end of the housing; an inner protector accommodating the detection portion of the detection element therein, the inner protector including a bottom portion having an exhaust hole, a circumferential portion having inner introduction holes for introducing the gas-to-be-measured into the interior of the inner protector, and a rear end portion fixed to a front end portion of the housing; and an outer protector enclosing the inner protector therein with a clearance present between the inner protector and the outer protector, the outer protector including a circumferential portion having outer introduction holes for introducing the gas-to-be-measured into the clearance, and a rear end portion fixed to the front end portion of the housing, wherein an axial distance h (mm) between a front end of the detection element and the exhaust hole and a diameter r (mm) of the exhaust hole satisfy a relation r≦2h/15+⅓, where 0<h and 0<r; wherein the diameter r of the exhaust hole is equal to or greater than 0.5 mm; and wherein the axial distance h between the front end of the detection element and the exhaust hole is equal to or less than 15 mm.