Patent ID: 7562555
Filing Date: 2009-07-21
Classification: B01D,G01N

Abstract:
1. A gas sensor comprising: a gas detection element in contact with a reference gas via a first surface and in contact with a gas to be measured via a second surface opposite the first surface; and a waterproof enclosure member defining, together with the gas detection element, an internal space to which the first surface of the gas detection element is exposed but the second surface of the gas detection element is not exposed; wherein the enclosure member includes a waterproof grommet, enclosing at least a portion of the internal space, having an air through-hole extending therethrough, establishing air communication between the internal space and an exterior of the gas sensor, and formed of a rubberlike elastic material; and the grommet has a water-repellent filter member fitted into the air through-hole thereof, allowing air communication between the internal space and the exterior of the gas sensor through the air through-hole, and preventing entry of water into the internal space through the air through-hole, wherein the water-repellent filter member is formed from a resin sheet of a porous, fibrous structure having air permeability and water repellency, the filter member comprising: a tubular side wall portion; and a bottom wall portion closing one end of the tubular side wall portion, fibers of the resin sheet being fused together at the tubular side wall portion so as to enhance rigidity thereof, and at least a portion of the bottom wall portion maintaining the porous, fibrous structure of the resin sheet and thereby having air permeability.