Abstract: A system for testing an evaporative emissions (EVAP) canister of a vehicle according to the present disclosure includes an evaporator configured to contain liquid fuel, a fuel vapor supply line configured to deliver a mixture of fuel vapor and carrier gas from the evaporator to the EVAP canister, and a fuel vapor supply valve disposed in the fuel vapor supply line. The test system further includes a gas density meter configured to measure a density of the fuel vapor mixture flowing through the fuel vapor supply line, and a valve control module configured to control a position of the fuel vapor supply valve to adjust a flow of fuel vapor from the evaporator to the EVAP canister based on the fuel vapor mixture density.

Abstract: 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.

Abstract: A method for providing a visual aid to guide a driver when executing a test cycle includes controlling an electronic display to display a graph including a target trace indicating a target speed of a vehicle during the test cycle and a first visual indicator of an actual speed of the vehicle during the test cycle, scroll the target trace from a first side of the graph to a second side of the graph during a time-based portion of the test cycle to indicate the target vehicle speed with respect to an amount of time elapsed since a start of the test cycle, and scroll the target trace from the first side of the graph to the second side of the graph during a distance-based portion of the test cycle to indicate the target vehicle speed with respect to a distance travelled by the vehicle during the test cycle.

Abstract: 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.

Abstract: An emissions test system includes a dilution tunnel, a clean circuit, a dirty circuit, and a sampling control module. The dilution tunnel is configured to receive exhaust gas from an engine and dilution gas from a dilution gas source. The clean circuit is configured to receive gas from the dilution tunnel. The dirty circuit is configured to receive gas from the dilution tunnel independent of the clean circuit. The sampling control module is configured to direct gas from the dilution tunnel to the dirty circuit when the engine is off at the start of a first test phase. The sampling control module is configured to direct gas from the dilution tunnel to the clean circuit at the end of the first test phase when the engine is switched on during the first test phase.

Abstract: An exhaust sampling system includes a dilution tunnel in which exhaust gas from an engine is diluted with a diluent gas, a sample probe in fluid communication with the dilution tunnel, a sample collector, a first flow path in fluid communication with the sample probe and the sample collector, a source of fill gas, a second flow path in fluid communication with the source of fill gas and the sample collector, and a controller that selectively supplies the diluted exhaust gas to the sample collector through the first flow path during a test phase, and that selectively supplies the fill gas to the sample collector through the second flow path during the test phase. At least a portion of the second flow path is different than the first flow path.

Abstract: A system for testing an evaporative emissions (EVAP) canister of a vehicle according to the present disclosure includes an evaporator configured to contain liquid fuel, a fuel vapor supply line configured to deliver a mixture of fuel vapor and carrier gas from the evaporator to the EVAP canister, and a fuel vapor supply valve disposed in the fuel vapor supply line. The test system further includes a gas density meter configured to measure a density of the fuel vapor mixture flowing through the fuel vapor supply line, and a valve control module configured to control a position of the fuel vapor supply valve to adjust a flow of fuel vapor from the evaporator to the EVAP canister based on the fuel vapor mixture density.

Abstract: A system according to the present disclosure includes a pressure sensor and an engine state module. The pressure sensor is configured to measure pressure in an exhaust gas supply line that supplies exhaust gas from an engine to an emissions measurement system. The emissions measurement system includes a dilution tunnel, a sample probe, and a sample collector. The exhaust gas is diluted with a dilution gas in the dilution tunnel, and the sample probe supplies a portion of the diluted exhaust gas to the sample collector. The engine state module is configured to determine whether the engine is on or off based on at least one of (i) a frequency of pulsations in the exhaust gas supply line pressure and (ii) a magnitude of the pulsations in the exhaust gas supply line pressure.

Abstract: An exhaust gas sampling system according to the principles of the present disclosure includes a dilution air source that provides dilution air to a first flow path and a first flow meter that measures a first mass flow rate in the first flow path. The system further includes a sampling probe, a second flow meter, a first valve, and a leak detection module. The sampling probe provides exhaust gas to the first flow path at a location downstream from the first flow meter. The second flow meter measures a second mass flow rate in the first flow path at a location downstream from the sampling probe. The first valve regulates exhaust gas flow from the sampling probe to the second flow meter. The leak detection module detects a leak in the system based on measurements of the first and second mass flow rates taken when the first valve is closed.

Abstract: Disclosed is a method of correcting a response of an instrument. The method includes determining an inverse convolution function, the inverse convolution function being in the time domain. A response of an instrument to an exhaust sample is recorded as a function of time. The recorded response is then convolved with the inverse convolution function, the result being a convolution corrected instrument response.

Abstract: An exhaust sampling system for an engine is provided. The exhaust sampling system may include a source of exhaust gas, an exhaust collection unit including at least one collection bag that selectively receives the exhaust gas, and a sample probe in fluid communication with the source of exhaust gas that selectively supplies the at least one collection bag with the exhaust gas. The exhaust sampling system may also include a controller that permits flow of the exhaust gas from the sample probe to the at least one collection bag in a first state and prevents flow of the exhaust gas from the sample probe to the at least one collection bag in a second state. The controller may determine an extraction rate of the sample probe based on an ON time of the engine during a test phase.

Abstract: An engine emissions test system according to the principles of the present disclosure includes a sampling conduit, at least one sample bag, a read circuit, and a fill circuit. The sampling conduit is configured to receive exhaust from an engine. The at least one sample bag is configured to store a sample of exhaust. The read circuit is configured to communicate the stored sample of exhaust between the at least one sample bag and an analyzer. The fill circuit includes a fill gas line configured to provide a fill gas to be mixed with the sample of exhaust. The fill gas line extends between a fill gas source and the read circuit.

Abstract: An emissions test apparatus is provided and may include a filter housing having at least one of a first RFID tag and a first bar code identifying the filter housing. A filter media may be selectively disposed within the filter housing and may include at least one of a second RFID tag and a second bar code identifying the filter media. A controller may link the filter housing and the filter media when the filter media is disposed within the filter housing based on information provided by the at least one of the first RFID tag and the first bar code and the at least one of the second RFID tag and the second bar code.

Abstract: A dual-purpose dynamometer assembly is disclosed including a dynamometer motor, a chassis dynamometer roll that can be driven by a vehicle wheel, and a powertrain dynamometer shaft that can be driven by a vehicle powertrain. A gearbox is disposed between and rotatably couples the dynamometer motor with the chassis dynamometer roll and the powertrain dynamometer shaft. At least one chamber wall defining a test chamber is disposed between the dynamometer motor on one side and the chassis dynamometer roll and the powertrain dynamometer shaft on the other side such that the dynamometer motor is disposed outside of the test chamber. There is at least one aperture penetrating the chamber wall through which the dynamometer motor is connected to the chassis dynamometer roll and the powertrain dynamometer shaft. Accordingly, the dynamometer motor is isolated from extreme temperatures within the test chamber.

Abstract: An exhaust sampling system for an engine is provided. The exhaust sampling system may include a source of exhaust gas, an exhaust collection unit including at least one collection bag that selectively receives the exhaust gas, and a first sample probe in fluid communication with the source of exhaust gas that selectively supplies the at least one collection bag with the exhaust gas at an extraction rate. The exhaust sampling system may also include a controller that permits flow of the exhaust gas from the first sample probe to the at least one collection bag in a first state and prevents flow of the exhaust gas from the first sample probe to the at least one collection bag in a second state. The controller may control the extraction rate of the first sample probe based on a time during a test phase at which the engine is switched to an ON state.

Abstract: A system and method is provided for synchronizing a first and second signal of an exhaust sampling system. The first signal is generated by a first instrument and includes an exhaust flow rate component and a first instrument time stamp component. The second signal is generated by a second instrument and includes a pollutant concentration component and a second instrument time stamp component. The second instrument also generates a tertiary signal that has been influenced by the first signal and includes a second instrument time stamp component. A synchronization module determines a time relationship for synchronizing the first signal and the second signal by comparing the first flow rate component and the first instrument time stamp component of the first signal to the tertiary signal and the second instrument time stamp component of the tertiary signal. The synchronization provides accurate calculation of a pollutant mass flow rate.

Abstract: Disclosed is an exhaust sampling system including a plurality of exhaust sampling system zones. The zones are, at least, a sampling conduit, a fill circuit, and a read circuit. A controller is programmed to predict a minimum dilution ratio to avoid condensation in one of the exhaust sampling system zones. The controller is further programmed to run a test procedure in which a sample of exhaust is diluted with a make-up gas at a selected minimum dilution ratio that is greater than or equal to the predicted minimum dilution ratio. Further disclosed are methods of predicting whether condensation occurs during a test procedure.

Abstract: An emissions test apparatus is provided and may include a filter housing having at least one of a first RFID tag and a first bar code identifying the filter housing. A filter media may be selectively disposed within the filter housing and may include at least one of a second RFID tag and a second bar code identifying the filter media. A controller may link the filter housing and the filter media when the filter media is disposed within the filter housing based on information provided by the at least one of the first RFID tag and the first bar code and the at least one of the second RFID tag and the second bar code.

Abstract: Disclosed is a vehicle emissions monitoring system capable of providing an accurate, real-time estimate of an amount of particulate matter (PM) within a vehicle's exhaust. The system is capable of accurately differentiating the composition of that PM by identifying amounts attributable to soot, SOF, and sulfate.

Abstract: An exhaust sampling system includes a pre-fill gas source having a pre-fill gas. A sampling conduit is configured to collect exhaust gas and make-up gas. A sample bag is fluidly connected to the sampling conduit and the pre-fill gas source. A controller is programmed to run a test procedure in which a sample of exhaust gas and make-up gas is collected in the sample bag. The controller sends a command that fills the sample bag with pre-fill gas prior to the test procedure. The pre-fill gas remains in the sample bag during the test procedure. In one example, the amount of pre-fill gas is selected to prevent the sample from condensing in the sample bag during the test procedure. In another example, the amount of pre-fill gas is selected to provide a sufficient volume of gases for analysis during the test procedure.