Apparatus and associated methods relate to a one-piece structure for a solid electrolyte chemical sensor (SECS) having a first surface defining a cavity (210, 305, 415) designed to receive a substrate (215, 350, 410) that retains a solid electrolyte (365, 440), an internal water impermeable coating (425) on at least a portion of the first surface, a second surface that is substantially coplanar with an adjacent peripheral edge of a top surface of the substrate (215, 350, 410) when the substrate (215, 350, 410) is received in the cavity (210, 305, 415), and a plurality of electrical contacts (335, 340, 345, 450a-450b) disposed on the second surface adapted to electrically couple with the electrodes (435a-435c) on the substrate (215, 350, 410) when the substrate (215, 350, 410) is received in the cavity (210, 305, 415) and electrical paths are provided between respective electrical contacts (335, 340, 345, 450a-450b) and electrodes (435a-435c).

Electrochemical sensors include a housing within which an electrolyte is provided over the electrodes. The housing includes an active region, which is the area around the electrodes in which the electrolyte must be positioned to ensure correct operation of the device. The inner walls, base and ceiling of the housing are coated in either hydrophobic or hydrophilic materials, or both, so as to encourage the electrolyte to take a position over the active region, which is defined by the position of the electrodes. In some electrochemical sensors, a combination of hydrophobic and hydrophilic materials is used and the materials can be arranged in a pattern, which encourages the electrolyte to take a position over the active region.

A gas sensor (100) extending in an axial direction AX including: a gas sensor element (120) which detects the concentration of a specific gas in a gas under measurement; a tubular metallic shell (110) having a polygonal tool engagement portion (110B) surrounding the gas sensor element (120); a tubular outer tube (103) which extends rearward from the metallic shell (110), surrounds the gas sensor element (120), and has an opening (103E) at a rear end thereof; a sealing member (191) which seals the opening (103E); and a tubular heat dissipating member (104) which surrounds the outer tube (103) and reduces the amount of heat transferred from the forward end side of the gas sensor (100) through the outer tube (103) to the sealing member (191). The maximum diameter D1 of the heat dissipating member (104) is equal to or less than the opposite side dimension D2 of the tool engagement portion (110B).

A gas sensor includes: a sensor element; a ceramic housing holding a rear end portion of the sensor element and provided with metal terminals electrically connected to the sensor element; and an elastic insulating member that is fixed in the rear of the sensor element and into which a plurality of lead wires electrically connected to the metal terminals are inserted. The elastic insulating member has one or more common spaces formed in a surface of the elastic insulating member that faces the ceramic housing. Two or more of the lead wires are arranged in each common space.

An exhaust sensor includes a sensing element with a ceramic sensing element substrate and a sensing element terminal which is electrically conductive and which is supported by the ceramic sensing element substrate such that the sensing element is configured to sense constituents of exhaust gases when exposed thereto. The exhaust sensor also includes a mating terminal which is electrically conductive and which is in electrical communication with the sensing element terminal. The mating terminal has a base material and a clad material bonded to the base material such that the clad material contacts the sensing element terminal and such that the clad material is located between the sensing element terminal and the base material, thereby providing the electrical communication. The clad material is an alloy which is less than or equal to 20% iron, greater than or equal to 40% nickel, and greater than or equal to 13% chromium.

A gas sensor includes a sensor element, a tubular body made of metal, and a sealing material. The sensor element has a surface. The tubular body has a through hole which is formed along the axial direction and through which the sensor element is inserted. The sealing material is placed inside the through hole and between the inner peripheral surface of the through hole and the sensor element. The sealing material covers a part of the surface of the sensor element. When the sensor element is viewed in cross section from a second direction perpendicular to a first direction corresponding to the longitudinal direction of the sensor element, the sealing material forms a first inclination angle of not less than 10° and not more than 80° with respect to the surface.

A gas sensor includes a sensor element, an inner protective cover including a first member and a second member, and an outer protective cover having outer inlets. The inner protective cover has a sensor element chamber inside. The outer protective cover and the inner protective cover form an inlet-side gas flow channel from an outside to the sensor element chamber. The inlet-side gas flow channel has a first flow channel extending in an upward direction from the outer inlets and a second flow channel extending in a downward direction. A ratio W2/W1 between a flow channel width W1 of the first flow channel and a flow channel width W2 of the second flow channel is less than one. A tip end portion of the outer protective cover has a tapered portion that reduces in diameter toward a bottom portion of the tip end portion.

Apparatus and associated methods relate to a one-piece structure for a solid electrolyte chemical sensor (SECS) having a first surface defining a cavity designed to receive a substrate that retains a solid electrolyte, an internal water impermeable coating on at least a portion of the first surface, a second surface that is substantially coplanar with an adjacent peripheral edge of a top surface of the substrate when the substrate is received in the cavity, and a plurality of electrical contacts disposed on the second surface adapted to electrically couple with the electrodes on the substrate when the substrate is received in the cavity and electrical paths are provided between respective electrical contacts and electrodes. In an illustrative example, the internal water impermeable coating may include a metallic material, such as gold. In various embodiments, the one-piece structure may advantageously prevent water loss from both the sensor substrate and the SECS.

Various example embodiments described herein relate to an electrochemical gas sensor. The electrochemical gas sensor can include a sensor cap having one or more solid features disposed on a surface of the sensor cap. The electrochemical gas sensor can include a counter electrode configured to generate a gas during use of the electrochemical gas sensor. The electrochemical gas sensor can include a vent assembly adapted to release at least a portion of the gas generated at the counter electrode out from the electrochemical gas sensor. The vent assembly can include a vent conduit and a vent membrane that defines a passage for the gas to flow from an extended portion of the counter electrode, to the vent conduit, via the vent membrane, so as to be vented from the electrochemical gas sensor.

A gas sensor includes a sensor element, an elastic insulating member, a plurality of lead wires, a plurality of metal terminals, and a ceramic housing. The plurality of lead wires are inserted in the elastic insulating member. The plurality of metal terminals each have a first end electrically connected to the sensor element, and a second end electrically connected to a corresponding one of the plurality of lead wires. The ceramic housing includes a plurality of insertion portions each including a through hole in which a corresponding one of the plurality of metal terminals is inserted, and at least one of the plurality of insertion portions has a different height from other insertion portions.