Abstract: A gas sensor includes a metallic shell extending along a shell axis and defining a shell attaching surface that is substantially perpendicular to the shell axis; a metallic shield extending along a shield axis and defining a shield attaching surface that is substantially perpendicular to the shield axis; and a ceramic sensing element extending along a sensing element axis, the sensing element being rigidly fixed at a first axial location of the sensing element to the shell and the sensing element being laterally supported by the shield at a second axial location of the sensing element that is axially spaced apart from the first axial location. The shield is attached to the shell at an interface formed between the shield attaching surface and the shell attaching surface, thereby accommodating misalignment between the shield axis and the shell axis. A method of making the gas sensor is also provided.

Abstract: A gas sensor includes a metallic shell with a shell aperture extending therethrough along an axis; a metallic glass holder metallurgically sealed to the shell in order to prevent gases from passing between the glass holder and the shell, the glass holder including a glass holder aperture extending axially therethrough; a ceramic sensing element extending through the shell aperture and through the glass holder aperture; and a glass seal which seals between the sensing element and the glass holder in order to prevent gases from passing between the sensing element and the glass holder. A method of making the gas sensor is also provided.

Abstract: A gas sensor includes a metallic shell extending along a shell axis and defining a shell attaching surface that is substantially perpendicular to the shell axis; a metallic shield extending along a shield axis and defining a shield attaching surface that is substantially perpendicular to the shield axis; and a ceramic sensing element extending along a sensing element axis, the sensing element being rigidly fixed at a first axial location of the sensing element to the shell and the sensing element being laterally supported by the shield at a second axial location of the sensing element that is axially spaced apart from the first axial location. The shield is attached to the shell at an interface formed between the shield attaching surface and the shell attaching surface, thereby accommodating misalignment between the shield axis and the shell axis. A method of making the gas sensor is also provided.

Abstract: A gas sensor includes a metallic shell with a shell aperture extending therethrough along an axis; a metallic glass holder metallurgically sealed to the shell in order to prevent gases from passing between the glass holder and the shell, the glass holder including a glass holder aperture extending axially therethrough; a ceramic sensing element extending through the shell aperture and through the glass holder aperture; and a glass seal which seals between the sensing element and the glass holder in order to prevent gases from passing between the sensing element and the glass holder. A method of making the gas sensor is also provided.

Abstract: A diagnostic method and system is described for diagnosing an operating condition of a conductive particulate matter sensor. The sensor has a substrate with electrical resistance that varies with temperature and two electrodes on the substrate adapted to collect particulate matter between the electrodes, thereby establishing an electrically conductive path through collected particulate matter between the electrodes that can be detected by measuring electrical resistance between the electrodes, Relect. The diagnosis is performed by heating the substrate in the area between the electrodes and detecting whether resistance varies with temperature as expected, and then cooling the substrate back down and detecting whether resistance varies with temperature as expected. If resistance varies as expected during both heating and cooling, then a validation is diagnosed that the sensor is in proper operating condition if resistance increases in a manner consistent with evaporation of condensate.

Abstract: A diagnostic method and system is described for diagnosing an operating condition of a conductive particulate matter sensor. The sensor has a substrate and two electrodes on the substrate adapted to collect particulate matter between the electrodes, thereby establishing an electrically conductive path through collected particulate matter between the electrodes that can be detected by measuring electrical resistance between the electrodes, Relect. The diagnosis is performed by detecting whether water vapor condensate may be present between the electrodes and if it is, then measuring resistance between the electrodes while subjecting the sensor to conditions sufficient to evaporate any water vapor condensate and diagnosing a validation that the sensor is in proper operating condition if resistance increases in a manner consistent with evaporation of condensate.

Abstract: A particulate matter sensor is provided for sensing particulate matter present in exhaust gases in a conduit. The particulate matter sensor includes a sensing element with a sensing face which extends into the exhaust conduit and provides a signal indicative of the amount of particulate matter detected in the exhaust conduit. An inner shield is provided to surround the sensing face and includes an inner shield inlet for admitting exhaust gases therein to be sensed. An outer shield surrounds a portion of the inner shield and defines an outer shield chamber extending axially beyond the inner shield. The outer shield has an outer shield inlet passage to receive exhaust gasses from the conduit. Exhaust gases enter the inner shield from the outer shield chamber through the inner shield inlet.

Abstract: A soot sensor and method for detecting soot is provided. In one exemplary embodiment, a sensing element for a soot sensor is disclosed herein, the sensing element having a pair of peripheral edge sensing electrodes each having a portion disposed on a peripheral edge of a non-conductive substrate of the sensing element; a first pair of side sensing electrodes disposed on a first side of the sensing element, the first side having a first area partially bounded by the peripheral edge, wherein a resistance between the pair of peripheral edge sensing electrodes decreases as soot accumulates on portions of the pair of peripheral edge sensing electrodes and a resistance between the first pair of side sensing electrodes decreases as soot accumulates on portions of the first pair of side sensing electrodes.

Abstract: A gas sensor with a high temperature electrical connector is provided. The electrical connector incorporates a ceramic connector body having a pair of opposing ceramic body portions which each house a plurality of conductive terminals. The body portions are in pivoting engagement and fixed in a connector body retainer which also enables their pivoting, hinged movement. The pivoting engagement permits the ceramic body portions and terminals to hinge open to receive a gas sensor with a low insertion force and a hinge closed to provide the desired contact force.

Abstract: A particulate matter sensor is provided for sensing particulate matter present in exhaust gases in a conduit. The particulate matter sensor includes a sensing element with a sensing face which extends into the exhaust conduit and provides a signal indicative of the amount of particulate matter detected in the exhaust conduit. An inner shield is provided to surround the sensing face and includes an inner shield inlet for admitting exhaust gases therein to be sensed. An outer shield surrounds a portion of the inner shield and defines an outer shield chamber extending axially beyond the inner shield. The outer shield has an outer shield inlet passage to receive exhaust gasses from the conduit. Exhaust gases enter the inner shield from the outer shield chamber through the inner shield inlet.

Abstract: An ablating device is used to form a pattern into a sensing element pad of a soot sensor, with the pattern establishing two finger paths without electrical connection between them. The pattern can be formed through a protective layer on the sensing element pad before the sensing element pad is fired.

Abstract: A diagnostic method and system is described for diagnosing an operating condition of a conductive particulate matter sensor. The sensor has a substrate and two electrodes on the substrate adapted to collect particulate matter between the electrodes, thereby establishing an electrically conductive path through collected particulate matter between the electrodes that can be detected by measuring electrical resistance between the electrodes, Relect. The diagnosis is performed by detecting whether water vapor condensate may be present between the electrodes and if it is, then measuring resistance between the electrodes while subjecting the sensor to conditions sufficient to evaporate any water vapor condensate and diagnosing a validation that the sensor is in proper operating condition if resistance increases in a manner consistent with evaporation of condensate.

Abstract: A diagnostic method and system is described for diagnosing an operating condition of a conductive particulate matter sensor. The sensor has a substrate with electrical resistance that varies with temperature and two electrodes on the substrate adapted to collect particulate matter between the electrodes, thereby establishing an electrically conductive path through collected particulate matter between the electrodes that can be detected by measuring electrical resistance between the electrodes, Relect. The diagnosis is performed by heating the substrate in the area between the electrodes and detecting whether resistance varies with temperature as expected, and then cooling the substrate back down and detecting whether resistance varies with temperature as expected. If resistance varies as expected during both heating and cooling, then a validation is diagnosed that the sensor is in proper operating condition if resistance increases in a manner consistent with evaporation of condensate.

Abstract: A ceramic connector body for a high temperature electrical connector, such as those used in high temperature gas sensors, incorporates a pair of opposing ceramic body portions which are operative for pivoting engagement and to be fixed in a connector body retainer which also enables their pivoting, hinged movement. The pivoting engagement permits the ceramic body portions to hinge open to receive a gas sensor with a low insertion force and a hinge close to provide the desired contact force. The ceramic body portions are also operative to house conductive terminals which provide electrical contact for power and signal communication with a gas sensor.

Abstract: A soot sensor and method for detecting soot is provided. In one exemplary embodiment, a sensing element for a soot sensor is disclosed herein, the sensing element having a pair of peripheral edge sensing electrodes each having a portion disposed on a peripheral edge of a non-conductive substrate of the sensing element; a first pair of side sensing electrodes disposed on a first side of the sensing element, the first side having a first area partially bounded by the peripheral edge, wherein a resistance between the pair of peripheral edge sensing electrodes decreases as soot accumulates on portions of the pair of peripheral edge sensing electrodes and a resistance between the first pair of side sensing electrodes decreases as soot accumulates on portions of the first pair of side sensing electrodes.

Abstract: A connector body retainer for a high temperature electrical connector used in a high temperature gas sensor retains the ceramic body portions while also permitting their hinged movement. The connector body retainer includes a pair of retainer bands each having a generally u-shaped or c-shaped profile with a base portion and a pair of opposed extending legs, the legs of each band extending toward the other in opposing arrangement to provide the retainer, with each retainer band having an outer surface, an inner surface, a hinge end and an insertion end. The legs of the respective bands which are in opposing arrangement are joined together by a respective pair of outwardly arched hinges proximate the hinge end and will allow the ceramic body portions to hinge open to receive a gas sensor at a relatively low insertion force and hinge closed to provide a relatively higher contact force.

Abstract: A ceramic connector body for a high temperature electrical connector, such as those used in high temperature gas sensors, incorporates a pair of opposing ceramic body portions which are operative for pivoting engagement and to be fixed in a connector body retainer which also enables their pivoting, hinged movement. The pivoting engagement permits the ceramic body portions to hinge open to receive a gas sensor with a low insertion force and a hinge close to provide the desired contact force. The ceramic body portions are also operative to house conductive terminals which provide electrical contact for power and signal communication with a gas sensor.

Abstract: A gas sensor with a high temperature electrical connector is provided. The electrical connector incorporates a ceramic connector body having a pair of opposing ceramic body portions which each house a plurality of conductive terminals. The body portions are in pivoting engagement and fixed in a connector body retainer which also enables their pivoting, hinged movement. The pivoting engagement permits the ceramic body portions and terminals to hinge open to receive a gas sensor with a low insertion force and a hinge closed to provide the desired contact force.

Abstract: A connector body retainer for a high temperature electrical connector used in a high temperature gas sensor retains the ceramic body portions while also permitting their hinged movement. The connector body retainer includes a pair of retainer bands each having a generally u-shaped or c-shaped profile with a base portion and a pair of opposed extending legs, the legs of each band extending toward the other in opposing arrangement to provide the retainer, with each retainer band having an outer surface, an inner surface, a hinge end and an insertion end. The legs of the respective bands which are in opposing arrangement are joined together by a respective pair of outwardly arched hinges proximate the hinge end and will allow the ceramic body portions to hinge open to receive a gas sensor at a relatively low insertion force and hinge closed to provide a relatively higher contact force.

Abstract: A connector assembly for a planar sensing element of an exhaust gas sensor is shown, with a method for assembling. There is an opposed pair of ceramic clamshells which retain terminals, each terminal mates to corresponding contact pads of the planar sensing element. A spacer is positioned between clamshells and a seal. A retainer clip binds the ceramic clamshells. These components are contained within an upper shield, upon assembly. The spacer creates a hinge point between the clamshell devices, allowing insertion of the sensing element without abrasion or scraping of the contact pads against the terminals The retainer clip, with radially extending tabs, keeps the opposed pair of ceramic clamshells under compression upon the sensing element when assembled, due to an interference fit with the upper shield of the sensor.