Abstract: A gas sensor includes a solid electrolyte body provided with a measured gas side electrode and a reference gas side electrode, a heater in the solid electrolyte body, a housing for holding the solid electrolyte body therein, and a cover for covering the solid electrolyte body. The cover has a large-diameter cover portion positioned on an outer circumferential side of the solid electrolyte body, a small-diameter cover portion positioned adjacent to a tip side of the large-diameter cover portion and formed smaller than the large-diameter cover portion, and a stepped portion connecting the small-diameter cover portion and the large-diameter cover portion. A first through hole is formed at a tip of the small-diameter cover portion. A second through hole is formed at a plurality of positions in a circumferential direction of the stepped portion.

Abstract: A gas sensor includes a solid electrolyte body provided with a measured gas side electrode and a reference gas side electrode, a heater in the solid electrolyte body, a housing for holding the solid electrolyte body therein, and a cover for covering the solid electrolyte body. The cover has a large-diameter cover portion positioned on an outer circumferential side of the solid electrolyte body, a small-diameter cover portion positioned adjacent to a tip side of the large-diameter cover portion and formed smaller than the large-diameter cover portion, and a stepped portion connecting the small-diameter cover portion and the large-diameter cover portion. A first through hole is formed at a tip of the small-diameter cover portion. A second through hole is formed at a plurality of positions in a circumferential direction of the stepped portion.

Abstract: A gas sensor comprises an atmosphere-side cover, ventilation filter, and filter cover as well as a sensing element and housing. The atmosphere-side cover has i) a first section of a first diameter located on a tip-end side in a axial direction of the housing and fixed on an axially base end of the housing, ii) a second section of a second diameter smaller than the first diameter, the second section being located on an axially base-end side, iii) a stepped section formed between the first and second sections, and iv) a rib protruding outward from the second section and being formed between the stepped section and the second section. The ventilation filter is mounted on the second section and has an axially tip-end section being in contact with an axially base-end section of the rib. The filter cover fixes the ventilation filter between the second section and the filter cover.

Abstract: A gas sensor comprises an atmosphere-side cover, ventilation filter, and filter cover as well as a sensing element and housing. The atmosphere-side cover has i) a first section of a first diameter located on a tip-end side in a axial direction of the housing and fixed on an axially base end of the housing, ii) a second section of a second diameter smaller than the first diameter, the second section being located on an axially base-end side, iii) a stepped section formed between the first and second sections, and iv) a rib protruding outward from the second section and being formed between the stepped section and the second section. The ventilation filter is mounted on the second section and has an axially tip-end section being in contact with an axially base-end section of the rib. The filter cover fixes the ventilation filter between the second section and the filter cover.

Abstract: An improved structure of a gas sensor is provided which is designed to ensure the stability of a sensor output insensitive to thermal energy added to a sensor element. The sensor element has a sensing area located where a correct sensor output is produced free from heat added to the sensor element.

Abstract: A protective cover assembly of a gas sensor which is made up of an inner and an outer cover. The inner cover is disposed within the outer cover coaxially through a given clearance. The dimension of the clearance is defined within a range suitable for improving the response rate of the gas sensor while ensuring the effect of avoiding the damage such as cracks in a sensor element arising from wetting thereof with moisture contained in a measurement gas.

Abstract: A protective cover assembly of a gas sensor which is made up of an inner and an outer cover. The inner cover is disposed within the outer cover coaxially through a given clearance. The dimension of the clearance is defined within a range suitable for improving the response rate of the gas sensor while ensuring the effect of avoiding the damage such as cracks in a sensor element arising from wetting thereof with moisture contained in a measurement gas.

Abstract: A gas sensor has a housing, a gas sensing element held by the housing and having a gas contact portion and an element cover for covering the gas contact portion. The element cover has a double pipe structure formed by layering an outer pipe and an inner pipe. The outer pipe has an outer bottom portion having an outer bottom hole and an outer side portion having plural outer side holes. The inner pipe has an inner bottom portion having an inner bottom hole and an inner side portion having plural inner side holes disposed not to overlap the outer side holes. A spacing D of 0.2-1.0 mm is formed between the outer bottom portion and the inner bottom portion. As a result, flow resistance in the spacing D is relatively high, and the sample gas sufficiently and more smoothly flows toward the gas sensing element. Therefore, the element cover prevents condensed water from entering the inside of the gas sensor and improves response of the gas sensor.