The aerosol diluting apparatus includes a first diluting unit to provide a first modified sample flow by combining an aerosol sample flow with a first diluting gas flow, an ejector unit to draw the first modified sample flow from the first diluting unit to the ejector unit and to provide a second modified sample flow by mixing a second dilution gas flow with the first modified sample flow, a control unit, and a control valve, wherein the control unit and the control valve are arranged to adjust flow rate of the second dilution gas flow according to an inlet pressure of the aerosol sample flow, so as to keep the dilution factor of the diluting apparatus substantially independent of the inlet pressure.

Methods and systems are provided for pinpointing a source of degradation in a vehicle engine system. In one example, a method includes spinning an engine of a vehicle unfueled in a forward and a reverse direction, in no particular order, and recording a first intake air flow and a second intake air flow, respectively, in an intake of the engine, and where the source of degradation is indicated as a function of both the first air flow and the second air flow. In this way, the degradation of the vehicle engine system may be pinpointed as to being located in the intake manifold, the exhaust system, or the engine.

A process oxygen analyzer includes a process probe extendible into a flow of process combustion exhaust, the process probe having an oxygen sensor measurement cell. Measurement circuitry is coupled to the oxygen sensor measurement cell and configured to obtain a non-corrected indication of oxygen concentration relative to a combustion process based on an electrical characteristic of the oxygen sensor measurement cell. A controller is operably coupled to the measurement circuitry and is configured to obtain an indication of process pressure and selectively provide a corrected oxygen concentration output based on non-corrected indication of oxygen concentration and the indication of process pressure. A method of providing a process oxygen concentration using a process oxygen analyzer coupled to an industrial combustion process is also disclosed.

A diagnostic system and method that (a) that uses models indicative of both successful firing and skips to determine if cylinders of a skip fire controlled internal combustion engine have successfully fired or successfully skipped and (b) uses filtered exhaust gas pressure readings for detecting faults associated with EGR systems and/or turbocharger systems.

An engine system includes a delta pressure sensor configured to sense a pressure difference across an engine exhaust handling component and an electronic control system configured to determine a cold sensor condition permitting icing of the delta pressure sensor, determine a sensed pressure deviation condition indicative of deviation of the pressure difference sensed by the delta pressure sensor from a deviation limit, dynamically model a sensor heat transfer condition indicative of heating or cooling of the delta pressure sensor, determine that the sensor heat transfer condition is indicative of insufficient heating of the delta pressure sensor to mitigate icing of the delta pressure sensor, and determine an icing condition of the delta pressure sensor.

The present invention provides a testing device testing a multi-cylinder engine including a plurality of ports including an intake port and an exhaust port in a pseudo driving state. The device includes a plurality of pressure inspection units and at least one opening/closing mechanism. Each of the plurality of pressure inspection units includes a pipeline connected to one of the plurality of ports, a sensor for detecting a pressure in the pipeline and a valve for opening/closing the pipeline. The opening/closing mechanism includes one actuator and a transmission mechanism connected to the actuator and transmitting a driving force of the actuator to an operation unit of each of the plurality of valves to open and close the plurality of valves.

A system and method are provided for estimating an operating parameter of an exhaust manifold of an engine. In the system, a flow value is determined that corresponds to a flow rate of exhaust gas through an EGR conduit fluidly coupled between the exhaust manifold and the intake manifold. The EGR conduit includes an exhaust gas cooler disposed in-line with the EGR conduit and a property of the exhaust gas exiting an exhaust gas outlet of the cooler is measured. The operating parameter of the exhaust manifold is estimated as a function of at least the flow value and the property of the exhaust gas exiting the exhaust gas outlet of the cooler. Illustratively, the operating parameter of the exhaust manifold may be exhaust manifold pressure and/or temperature.

A diagnostic system and method for diagnosing the performance of a particulate matter (PM) filter of an exhaust system each involve receiving, by a controller from at least one sensor, a gas component measurement of exhaust gas flowing through the exhaust system and the PM filter. The controller calculates a conversion efficiency of the gas component by the PM filter and compares the calculated conversion efficiency to a predetermined conversion efficiency threshold indicative of an expected conversion efficiency of a flow-through catalyst. The controller then determines whether the PM filter is cracked or damaged based on the comparison between the calculated conversion efficiency and the predetermined conversion efficiency threshold.

A diagnostic system and method that (a) that uses models indicative of both successful firing and skips to determine if cylinders of a skip fire controlled internal combustion engine have successfully fired or successfully skipped and (b) uses filtered exhaust gas pressure readings for detecting faults associated with EGR systems and/or turbocharger systems.

Disclosed is a method for diagnosing functionality of dosing units of a fluid dosing system comprising at least two dosing units, a tank unit for holding a fluid, and a pump unit for pressurizing the fluid for the dosing units. The method comprises determining a first hydraulic stiffness value on the basis of first pressure variations and determining a second hydraulic stiffness value on the basis of said second pressure variations. The first hydraulic stiffness value and second hydraulic stiffness value are compared. In a case where the first hydraulic stiffness value and second hydraulic stiffness value differ to a certain extent, concluding that malfunction of at least one of said dosing units is at hand, and in a case where the first hydraulic stiffness value and the second hydraulic stiffness value do not differ to said certain extent, concluding that the first and second dosing units function as intended.