Various embodiments include a sensor for use in an exhaust gas stream of an internal combustion engine comprising: a first electrode; a second electrode electrically insulated from the first electrode by an insulation; and a connection arrangement secured to the first electrode and the insulation by a solder connection. The connection arrangement is configured to position the first electrode relative to the second electrode. The solder connection is arranged at least partly outside an electric field generated during measurement operation of the sensor by applying a first electrical potential to the first electrode and applying a second, different, electrical potential to the second electrode.

A sensor device is equipped with a housing having an element cover retaining a sensor element such that a detection section of the sensor element is positioned at the tip end of the sensor element. The element cover includes an inner cover provided with inner side holes and an inner tip face hole respectively provided therein, and an outer cover provided with outer side holes in a side thereof, with the tip position of the outer side holes located closer to the tip end than is the tip position of the inner cover. Between the outer surface of the inner cover and the inner surface of the outer cover there is a large clearance section at the tip end and a small clearance section at the base end, providing a flow path that is shaped for connecting the large clearance section and the small clearance section without a step.

A sensor device includes an element cover at the tip end of a housing, retaining a sensor element. An outer cover is provided with outer side holes, with the tip position of the outer side holes being farther toward the tip end than is the tip position of an inner cover, and a first flow passage having a gas flow direction that is at right angles to the axial direction is formed at the inner side of the outer cover. An inner side hole in the inner cover is open to a second flow passage provided between the side surfaces of the inner cover and the outer cover, and a detection surface of the sensor element is located on an extension line in an extension direction of a guide member which extends obliquely into the interior of the inner cover from the tip-position edge of the inner side hole.

Various embodiments include an exemplary apparatus and method for insitu calibration of multiple flow-sensing devices within a dilution system. In one example, a calibration and dilution system includes a first mass-flow device to serve as a global reference, a second mass-flow device configured to be coupled to and provide a supply of clean gas to a primary diluter, and a third mass-flow device configured to be coupled to and provide a supply of clean gas to a secondary diluter, where the diluters are pneumatically coupled to one another through a gas-supply line. Multiple valves are coupled to at least the mass-flow devices and the diluters. The calibration and dilution system is arranged so that the mass-flow controllers can be calibrated in-situ without having to remove any of the mass-flow controllers from the calibration and dilution system. Other apparatuses, designs, and methods are disclosed.

An exhaust gas sampling system includes a main conveying line, a main throughput pump which conveys a sample gas in the main conveying line, a first Venturi nozzle, a second Venturi nozzle, a first control valve, and a second control valve. The first Venturi nozzle and the second Venturi nozzle are connected in parallel and are arranged in the main conveying line upstream of the main throughput pump. The first Venturi nozzle is assigned the first control valve. The second Venturi nozzle is assigned the second control valve. Each of the first control valve and the second control valve are provided as a pinch valve. Each pinch valve has a flexible, hose-like control element and a pressure chamber which is filled with a fluid and which is arranged to surround the flexible, hose-like control element.

A sensor element includes: an element base including: a ceramic body made of an oxygen-ion conductive solid electrolyte, and having a gas inlet at one end portion thereof; at least one internal chamber located inside the ceramic body, and communicating with the gas inlet under predetermined diffusion resistance; an electrochemical pump cell including an electrode located on an outer surface of the ceramic body, an electrode facing the internal chamber, and a solid electrolyte located therebetween; and a heater buried in the ceramic body, and a leading-end protective layer being porous, and covering a leading end surface and four side surfaces in a predetermined range of the element base on the one end portion. The leading-end protective layer has an extension extending into a widened portion included in the gas inlet, and fixed to an inner wall surface of the widened portion.

An environmental sampling system includes a passage in an aircraft component and a removable collector disposed in the passage. The passage has an inlet at a first region and an outlet at a second region. When the aircraft component is in operation the first region is at a greater pressure than the second region such that air flows through the passage from the inlet to the outlet. The removable collector is configured to retain constituents from the air and to react with the media designed to mimic corrosion effects seen at higher temperatures on engine parts. The constituents can then be characterized and correlated to engine deterioration to predict maintenance activity.

An example of an emissions test system according to the principles of the present disclosure includes a dilution tunnel and a flow control module. Exhaust gas is mixed with dilution gas in the dilution tunnel. The dilution tunnel is configured to receive dilution gas flowing in an axial direction relative to the dilution tunnel and dilution gas flowing in a radial direction relative to the dilution tunnel. The flow control module is configured to adjust the rate of the dilution gas flow in the radial direction based on at least one of a concentration of pollutant particles in the exhaust gas, a size of pollutant particles in the exhaust gas, a concentration of a gaseous emission in the exhaust gas, a type of fuel combusted by an engine producing the exhaust gas, and a rate of fuel flow to cylinders of the engine.

A thermodenuder having a main tube with an outer wall, and a heater (23) arranged within the main tube. The heater is arranged in the center of a cross section through the main tube and is spaced apart from the outer wall of the main tube. The main tube has a main axis of extension, and the heater extends parallel to the main axis. The main tube has two openings that are arranged at opposing side faces of the main tube. A channel for an aerosol is arranged within the main tube between the heater and the outer wall and between the two openings. Furthermore, a method for removing semi-volatile material and semi-volatile particles from an aerosol is provided.

An emissions test system includes an emissions analyzer, a contamination index module, and a diagnostic module. The emissions analyzer is configured to determine a concentration of an emission in a sample of exhaust gas from an engine. The contamination index module is configured to determine a contamination index based on at least two of a flow rate of the exhaust gas sample, the concentration of the emission in the exhaust gas sample, an operating duration of the emissions test system, a pressure of the exhaust gas, and a temperature of the exhaust gas. The diagnostic module is configured to identify potential contamination of at least one of the emissions test system and a component in the emissions test system based on the contamination index.