Patent ID: 7708869

Claim:
A gas sensor comprising: a concentration detection element capable of detecting a concentration of a specified gas contained in measuring gases which pass through a measuring gas passage; a housing accommodating the concentration detection element and fixing the concentration detection element to the measuring gas passage so that the concentration detection element is exposed in a measuring gas flow; and a cylindrical cover body having a bottom part, accommodating a part of the concentration detection element exposed in the measuring gas flow, and the cylindrical cover body having a plural cylinder configuration composed of at least an inner cover and an outer cover of a different radius constructed in a concentric configuration to each other, wherein in the cylindrical cover body, a side surface gap is formed between an outer peripheral surface of the inner cover and an inner peripheral surface of the outer cover, side surface opening parts of the inner cover are formed at the upper part of the side surface of the inner cover so that the opening direction of each side surface opening part of the inner cover turns upward from the outside of the inner cover toward the inside of the inner cover, a plurality of bottom surface opening parts of the inner cover constructed in concentric with an axis of the inner cover is formed in the bottom surface of the inner cover, a plurality of side surface opening parts through which the measuring gases are introduced into the side surface gap is formed at the upper part of the side surface of the outer cover, a bottom surface gap is formed between the bottom surface of the outer cover and the bottom surface of the inner cover in which the bottom surface of the outer cover is positioned below the bottom surface of the inner cover, a bottom surface opening part is formed at a center of the bottom surface of the outer cover, close in position to the center of the bottom surface rather than the bottom surface opening parts of the inner cover.