Abstract: A gas sensor is disclosed including a sensor element, an element holder, an atmosphere-side insulator, an atmosphere-side cover, and a pressing member interposed between a shoulder portion of the atmosphere-side cover and a base end face of the atmosphere-side insulator. A heat-transfer restricting support member is associated with at least one of the shoulder portion of the atmosphere-side cover, the base end face of the atmosphere-side insulator and the pressing member to allow the pressing member to be held in contact with the shoulder portion of the atmosphere-side cover and the base end face of the atmosphere-side insulator in a minimum contact surface fore thereby restricting a heat transfer from a distal end of the gas sensor to a base end thereof.

Abstract: A gas sensor is disclosed having an element holder body with which a senor element is fixedly supported, and an atmosphere-side insulator covering a base portion of the sensor element and providing electrical connection between lead wires and terminal electrodes of the sensor element. The element holder body includes a housing and an element-side insulator fixedly mounted in the housing. The atmosphere-side insulator incorporates therein a plurality of spring terminals held in electrical contact with the electrode terminals of the sensor element. At least one of the element holder body and the atmosphere-side insulator carries thereon convexed portions with which the atmosphere-side insulator can tilt with respect to the element holder body.

Abstract: A gas sensor having an elastic insulating member including a longitudinal hole for receiving an air permeability filter assembly and a passage portion communications between the longitudinal hole and an outer side thereof.

Abstract: A powder filler is stuffed in a filler space defined between a housing and a gas sensing element so as to airtightly seal a clearance between the housing and the gas sensing element. The powder filler contains grains whose diameter is in a range from 80 ?m to 5,000 ?m when measured before being stuffed into the filler space. A weight percentage of the grains having the diameter of 80 ?m to 5,000 ?m is equal to or larger than 80% with respect to an overall weight of the powder filler.

Abstract: A gas sensor includes a sensor element holder, a porcelain insulator, an outer cover disposed on a housing to surround the porcelain insulator, and a sensor element disposed in the housing. The gas sensor also includes outside springs and at least one pair of terminal springs each of which is disposed between the porcelain insulator and the sensor element in abutment with the sensor element. The terminal springs work to form a nip in which a thickness of the sensor element is retained. The outside springs are disposed between the porcelain insulator and the outer cover and have a combined spring constant which is greater than or equal to that of the terminal springs, thereby causing external pressure to be transmitted more to the outside springs than to the terminal springs to suppress vibrations of the porcelain insulator effectively to avoid application of an undesirable impact to the sensor element.

Abstract: A gas sensor has a sensor element inserted in a cylindrical housing. A measured gas cover, provided at a distal end side of the housing, forms a measured gas environment at a distal end side of the sensor element. An atmospheric air cover, provided at a proximal end side of the housing, forms an atmospheric air environment at a proximal end side of the sensor element. A clearance between an inside surface of the housing and an outside surface of the sensor element is gastightly sealed with a sealing member including a plurality of powder filler layers to separate or isolate the measured gas environment from the atmospheric air environment.

Abstract: A gas sensor has a sensor element inserted in a cylindrical housing. A measured gas cover, provided at a distal end side of the housing, forms a measured gas environment at a distal end side of the sensor element. An atmospheric air cover, provided at a proximal end side of the housing, forms an atmospheric air environment at a proximal end side of the sensor element. A clearance between an inside surface of the housing and an outside surface of the sensor element is gastightly sealed with a sealing member including a plurality of powder filler layers to separate or isolate the measured gas environment from the atmospheric air environment.

Abstract: A gas sensing element comprises a solid electrolytic element, a measured gas sensing electrode provided on an outer surface of the solid electrolytic element, and a reference gas sensing electrode facing a reference gas chamber. A heater is accommodated in the reference gas chamber. A contact portion is provided on an outer cylindrical surface of the heater so that the contact portion is brought into contact with an inside surface of the solid electrolytic element defining the reference gas chamber. A heating peak position of the heater is in the vicinity of the contact portion.

Abstract: A powder filler is stuffed in a filler space defined between a housing and a gas sensing element so as to airtightly seal a clearance between the housing and the gas sensing element. The powder filler contains grains whose diameter is in a range from 80 &mgr;m to 5,000 &mgr;m when measured before being stuffed into the filler space. A weight percentage of the grains having the diameter of 80 &mgr;m to 5,000 &mgr;m is equal to or larger than 80% with respect to an overall weight of the powder filler.

Abstract: A gas sensor includes a sensor element. The sensor element has a solid electrolytic member, a measurement electrode, and a reference electrode. The measurement electrode is provided on the solid electrolytic member, and is exposed to a measurement gas. The reference electrode is provided on the solid electrolytic member, and is exposed to a reference gas. A heater operates for heating the sensor element. A portion of the heater contacts a portion of the sensor element. The temperature of the sensor element is increased to 300° C. by the heater in ten seconds after the start of activation of the heater.

Abstract: A gas sensing element comprises a solid electrolytic element, a measured gas sensing electrode provided on an outer surface of the solid electrolytic element, and a reference gas sensing electrode facing a reference gas chamber. A heater is accommodated in the reference gas chamber. A contact portion is provided on an outer cylindrical surface of the heater so that the contact portion is brought into contact with an inside surface of the solid electrolytic element defining the reference gas chamber. A heating peak position of the heater is in the vicinity of the contact portion.

Abstract: A gas sensor measuring a given component content in a gas is provided which has an outer and an inner metallic cover, a sensing unit, and an insulator. The sensing unit consists of a measuring electrode to be exposed to the gas to be measured and a reference electrode to be exposed to a reference gas in a reference gas chamber. The measuring electrode and the reference electrode are disposed adjacent each other through a solid electrolyte body. The inner metallic cover is installed on an end of a sensor housing. The outer metallic cover is installed on the periphery of the inner metallic cover. The insulator is mounted within the inner metallic cover and has formed therein holes through which sensor signal pickup leads pass. The insulator has an outer wall different in geometry from an inner wall of the inner metallic cover to define a portion of a reference gas passage therebetween which leads to the reference gas chamber.

Abstract: An air fuel ratio sensor having an externally located heat source and an optical fiber heat introduction member. The heat introduction member is inserted into an inside chamber of a sensor element having a U-shaped cross section, and is connected to the external heat source outside the sensor element for introducing heat from the external heat source into the inside chamber. The heat introduction member is further connected to a temperature detector outside the sensor body. Accordingly, an air fuel ratio sensor can have sufficient durability and sufficient starting performance, and a temperature inside the sensor element can be readily detected.

Abstract: A laminated type oxygen concentration sensor includes a laminated type oxygen concentration sensor element having a plate shape with a flange on a side surface thereof, and a housing in a tubular shape having an inclination seat inclined in a central axial direction thereof. The housing supports the laminated type oxygen concentration sensor element by contacting the inclination seat with the flange of the laminated type oxygen concentration sensor element at an outer circumference of the inclination seat. Since the sensor element is supported by contacting the flange with the inclination seat of the housing at the outer circumference of the inclination seat, the pressure per unit area imposed on the sensor element is minimized and cracking of the sensor element is prevented.

Abstract: In an oxygen gas sensor having a variable electrical characteristic dependent upon ambient oxygen concentration, a ceramic holding member having a hole for holding a plate sensor sensor element is disposed in a housing with the element inserted into the housing. During sensor assembly, powder is filled under pressure in the housing between a pressurized member and the ceramic holding member. The ceramic holding member has an inclined surface descending directly from an upper opening end of the holding hole to form an obtuse angle between the sensor element and the inclined surface, so that the powder can flow on the inclined surface smoothly during the powder filling and powder compressing operations. By taking this construction it is possible to provide an oxygen concentration sensor with no cracking of the element and easy mounting of the sensor element to the housing.