Patent ID: 7189363
Filing Date: 2007-03-13
Classification: G01N,Y10T

Abstract:
1. A gas detector comprising: a case having an interior wall surface constituting a flow channel therein, through which air flows; and a gas sensor which is disposed in the case and detects a change in the concentration of specific gas in the air flowing through the flow channel, wherein when the gas detector is disposed in a setup state, the case includes a chamber wall surface which constitutes a chamber occupying at least a portion of the flow channel belonging to the interior wall surface; and which includes a bottom wall surface for constituting a bottom surface of the chamber, a chamber entrance that is situated on a side of the chamber and opens toward an upstream portion of the flow channel, a chamber exit that is situated on a side of the chamber, opens toward a downstream portion of the flow channel, has a lower open edge remaining flush with or situated lower than the entrance of the chamber, and has a portion of the bottom wall surface taken as a portion of the open edge, and an air vent that is provided toward the exit of the chamber when viewed from the entrance of the chamber and at a position higher than the bottom wall surface and guides air to the gas sensor; and an entrance-side shielding member which is situated between the chamber entrance and the air vent, both belonging to the chamber; which shields the air vent when viewed from the entrance of the chamber; and which constitutes a first lower gap between the lowermost portion of the entrance-side shielding member and the bottom wall surface and circulates at least a portion of the air that has flowed into the chamber, and wherein the bottom wall surface constitutes a horizontal plane or assumes a plate-like shape which becomes lower as the bottom wall surface approaches the exit of the chamber.