A gas sensor is configured to inhibit wear of a metal member contacting with a member containing ceramic. The gas sensor comprising: a first member containing ceramic; and a metal member contacting with the first member, wherein a hardness h1 of a contact part of the metal member contacting with the first member is greater than a hardness h2 of a reference part exhibiting a maximum thickness of the metal member.

The invention provides sensing devices for measuring an electrochemical parameter in a reactor. The sensing devices include one or more electrodes, a fastener comprising a female part and a male part, a compressible sealant inside an internal cavity of the male part, a spacer inside the internal cavity of the male part adjacent to and abutting the compressible sealant, a connector for connecting the compressible sealant and the male part and a connector for connecting the spacer and the compressible sealant. The male part, compressible sealant and spacer include one or more channels through which one of the one or more electrodes passes.

A gas sensor 200 including: a sensor element 10; and a separator 166 storing a metal terminal 21 inside a passage hole 166h, wherein the metal terminal has a body portion 21a having a main surface 21m, a first engagement portion 21d, and a second engagement portion 21e, the separator further has a ledge portion 166a having a first rearward-facing surface 312 and a first frontward-facing surface 314, a front-end side of the first engagement portion protrudes/sinks outward/inward of the main surface, and the front end is opposed to the first rearward-facing surface, and in the main-surface direction, a maximum opening width W2 of each retention hole 166hs retaining the metal terminal one by one satisfies a relationship of W2<W1 with respect to a maximum width W1 of the metal terminal at a part where the second engagement portion is located.

A gas sensor includes: a sensor element including a sensing part on a side of one end portion thereof; a casing; and a connector disposed in the casing to electrically connect the sensor element to an outside, wherein the casing includes: an outer tube including a main portion in which a reference gas is included and a sealing portion being an end portion having a smaller diameter than the main portion, another end portion of the sensor element protruding to the main portion, a rubber seal member fitted into the sealing portion to seal the outer tube, and a spacer intervening between the seal member and the connector in the outer tube. The spacer includes a concave portion in an end surface on a side having contact with the connector, and has contact with the connector in the end surface except for the concave portion.

A gas sensor includes: a sensor element including a sensing part on one end portion thereof; a casing; and a connector disposed in the casing to electrically connect the sensor element to an outside, wherein the casing includes: an outer tube including a main portion in which a reference gas is included and a sealing portion with a diameter smaller than the main portion so that another end portion of the sensor element protrudes to the main portion; a rubber seal member fitted into the sealing portion; and a spacer intervening between the seal member and the connector, and the spacer is secured by being sandwiched between the connector and the seal member due to friction force acting on a contact surface with the seal member which occurs by that load acts on the spacer from the seal member in accordance with reduction in the diameter by swaging.

A gas sensor includes: a sensor element; a plurality of element pads formed on a rear end portion of the sensor element; and a plurality of contact members holding the rear end portion of the sensor element and electrically connected respectively to the plurality of element pads. The plurality of contact members include contact members that each have an outer end surface protruding out from a corresponding one of end surfaces of the sensor element.

A sensor component includes: a sensor part having a sensor body and a connection terminal extending from the sensor body; and a holder part for holding the sensor part, the connection terminal being resin-sealed by an exterior part that is connected to a conductor of a wire, wherein a melt part that melts during the molding of the exterior part is provided on an outer surface of the holder part that is arranged inside of the exterior part, and the melt part is arranged in a position separating the sensor body and a connection part where the connection terminal is connected to the conductor.

A sensor element includes an element main body in which a flow portion of a measurement-object gas is disposed, a measurement electrode disposed in the flow portion of a measurement-object gas, a measurement electrode lead having a first portion that is connected to the measurement electrode and that is disposed in the flow portion of a measurement-object gas and a second portion that is connected to the first portion and that is embedded in the element main body, a hermetic layer that is part of the element main body and that surrounds an end region of the second portion including the border with the first portion; and a lead insulating layer that is part of the element main body and that surrounds at least part of the second portion excluding the end region.

A sensor element includes: three electrode pads provided on the first main surface, and electrically connected to a connection terminal, the three electrode pads including; a pad group including two electrode pads which are arranged in a widthwise direction of the sensor element, and a single pad which is not overlapped with the pad group when viewed in a widthwise direction, the single pad including a main body portion which has a width greater than a clearance between the two electrode pads of the pad group, which is electrically connected to the connection terminal, and a connection portion which is connected to a conductor formed within a through hole extending within the sensor element in a thickness direction, and which is adjacent to a side surface of the main body portion.

A join is provided that includes a first joining partner, a second joining partner having a surface, an electrically insulating component connecting the first joining partner in the second joining partner so that the first joining partner is electrically insulated from the second joining partner and so that the first joining partner extends from the surface. The electrically insulating component has a structure between the first and second joining partners that elongates from the surface along the first joining partner. The electrically insulating component and/or the structure is an at least partially crystallized glass.