Patent ID: 6749732
Filing Date: 2004-06-15
Classification: G01N

Abstract:
A gas sensor having a length with a first and a second end opposed to each other comprising:a hollow cylindrical housing having a first end and a second end respectively adjacent the first and second ends of the gas sensor; a sensing element retained within said housing which has a length extending in a longitudinal direction of the gas sensor, including a sensing portion working to measure a concentration of a specified gas; and a cover assembly installed on the second end of said housing to define a gas chamber in which the sensing portion of said sensing element is disposed and into which the specified gas is admitted, said cover assembly having a length extending in the longitudinal direction of the gas sensor, including an outer and an inner cover, the outer cover having a first gas inlet hole formed in a side wall thereof, the inner cover having formed in a side wall thereof a second gas inlet hole which is located closer to the first end of the gas sensor than the first gas inlet hole of the outer cover, the inner cover being disposed within the outer cover with a given clearance between the outer and inner covers, wherein one of the outer and inner covers of said assembly has formed on the side wall thereof a shoulder which separates the clearance between the outer and inner covers into a wider and a narrower portion, and wherein the wider portion is located nearer the second gas inlet hole of the inner cover than the narrow portion.