Abstract: A vehicle exhaust measurement system is provided includes that a conduit having a conduit inlet and a conduit outlet. A make-up air tube is connected to and is in fluid communication with the conduit inlet. The make-up air tube provides make-up air for mixing an exhaust gas. A mixed gas tube is connected to and is in fluid communication with the conduit outlet. The mixed gas tube conveys a mixture of make-up air and exhaust gas to analysis equipment. In the preferred embodiment, the exhaust gas tube extends through an outer wall of the conduit. A mixing plate is arranged in either the conduit or the mixed gas tube with the exhaust gas tube extending to a position adjacent to the mixing plate. The exhaust gas tube conveys the exhaust gas to the mixing plate to mix the exhaust gas and the make-up air at the mixing plate.

Abstract: A particulate filter system is provided including an exhaust system transporting emissions from an engine. A filter such as a diesel particulate filter is disposed in the exhaust system. An acoustic sensor is associated with the exhaust system for detecting one or more frequencies passing through the filter. The frequency corresponds to a filter state indicative of a clean, full, loading, or failed filter. One or more acoustic sensors may fluidly or mechanically coupled to portions of the exhaust system to determine the frequency caused by the exhaust flow through the filter. The acoustic emissions from the filter may be used to compare to a known filter state to determine the present filter state. Alternatively, more sophisticated mathematical approaches may be used in which processed filter information is compared to a known filter state to determine the present filter state.

Abstract: An exhaust gas measurement system is provided that includes a probe to find a sample exhaust gas passageway for collecting exhaust gas. A stainless steel canister is fluidly connected to the probe for storing the exhaust gas. A pump fluidly interconnects the probe and the canister for transferring the exhaust gas from the probe to the canister. A pressure mass flow controller fluidly interconnects the probe and the canister and produces an exhaust gas flow measurement corresponding to the flow of the exhaust gas from the probe to the canister. A temperature sensor senses a temperature of the exhaust gas proximate to the pressure mass flow controller. The temperature sensor corrects the exhaust gas flow measurement based upon the temperature sensed. A pressure sensor senses a pressure of the exhaust gas proximate to the pressure mass flow controller. The temperature sensor corrects the exhaust gas flow measurement based upon the pressure sensed.

Abstract: A particulate sampler is provided for use in analyzing particulate matter in exhaust gas. The sampler includes a transfer tube assembly including a probe at least partially defining a sample exhaust gas passageway. The transfer tube assembly has a first end portion with an opening for receiving exhaust gas and extends to a second end portion. A mixer receives the second end portion and includes a dilution gas passageway for carrying a dilution gas. The dilution gas passageway is in communication with the sample exhaust gas passageway for introducing the dilution gas to the exhaust gas. A tunnel is connected to the mixer and includes a gas mixing passageway extending a length for homogeneously mixing the gases together. The gas mixing passageway tapers toward the second end portion to ensure that the particulate matter mixes with the gases along the length of the gas mixing passageway without collecting in a recirculating flow area.

Abstract: A particulate sampler is provided for conveying exhaust gas from exhaust gas source to analysis equipment. The particulate sampler includes a probe for receiving the exhaust gas and a transfer tube for conveying the exhaust gas from a tailpipe to a mixer. The mixer mixes the exhaust gas and a dilution gas from a dilution source. A dilution tunnel mixes and conveys the exhaust gas and dilution gas from the mixer to analysis equipment such as a filter or gas analyzers. A flow pulsation cancellation device includes an actuator in communication with at least one of the tailpipe, probe, transfer tube, mixer, and dilution tunnel for introducing a canceling pressure pulse to minimize the effects of pressures pulses present from the tailpipe within the sampler. The actuator may be a moveable membrane or a fluid flow control valve.

Abstract: An exhaust emission analysis system is provided that includes an exhaust and dilution gas source respectively providing exhaust and dilution gases. A dilution unit includes exhaust and dilution gas flow devices, such as mass flow controllers, fluidly connected to the exhaust and dilution gas sources, respectively. The metering device in the mass flow controllers defines a gas flow rate of gas from its respective gas source. The gas flow devices are fluidly connected at a connection that mixes the gases to provide a diluted exhaust gas having an incorrect dilution ratio. A water measurement device such as an analyzer measures the water content of the exhaust gas, preferably subsequent to dilution. A water content dilution signal corresponding to the water content in the exhaust gas is sent from the water measurement device to a control device.

Abstract: A particulate sampler is provided for use in analyzing particulate matter in exhaust gas. The sampler includes a transfer tube assembly including a probe at least partially defining a sample exhaust gas passageway. The transfer tube assembly has a first end portion with an opening for receiving exhaust gas and extends to a second end portion. A mixer receives the second end portion and includes a dilution gas passageway for carrying a dilution gas. The dilution gas passageway is in communication with the sample exhaust gas passageway for introducing the dilution gas to the exhaust gas. A tunnel is connected to the mixer and includes a gas mixing passageway extending a length for homogeneously mixing the gases together. The gas mixing passageway tapers toward the second end portion to ensure that the particulate matter mixes with the gases along the length of the gas mixing passageway without collecting in a recirculating flow area.

Abstract: A particulate sampler is provided for use in analyzing particulate matter in exhaust gas. The sampler includes a transfer tube assembly including a probe at least partially defining a sample exhaust gas passageway. The transfer tube assembly has a first end portion with an opening for receiving exhaust gas and extends to a second end portion. A mixer receives the second end portion and includes a dilution gas passageway for carrying a dilution gas. The dilution gas passageway is in communication with the sample exhaust gas passageway for introducing the dilution gas to the exhaust gas. A tunnel is connected to the mixer and includes a gas mixing passageway extending a length for homogeneously mixing the gases together. The gas mixing passageway tapers toward the second end portion to ensure that the particulate matter mixes with the gases along the length of the gas mixing passageway without collecting in a recirculating flow area.

Abstract: A suspended large, single roll dynamometer for use in a compact pit. The dynamometer includes a power absorption unit operably coupled to a pair of rolls. The rolls support the driven wheels of a vehicle thereon for rotational movement. A cradle is used to support the power absorption unit, and thus the rolls, within the pit in a manner which does not require significant clearance between the perimeter of the cradle or the rolls and the interior walls of the pit. The components associated with the dynamometer which require periodic access and/or maintenance are further disposed on the power absorption unit so as to be readily physically accessible by an individual without physically entering the pit.