Abstract: A remote emissions sensing system and method for sensing exhaust emissions from motor vehicles is provided where the system determines the opacity of an exhaust plume. The system comprises a radiation source that emits radiation which is passed through the exhaust plume of a motor vehicle to one or more detectors arranged to receive the radiation. Multiple wavelength opacity measuring embodiments and monochromatic wavelength opacity measuring embodiments are disclosed.

Abstract: A remote sensing device is provided to detect the emissions of passing vehicles. Preferably, the device detects the emissions of individual vehicles traveling on a roadway of more than one traffic lane. The remote sensing device may preferably detect the emissions due to an individual vehicle in situations where more than one vehicle is present. The device is capable of determining which sensed emission data corresponds to which vehicle exhaust plume.

Abstract: A remote emissions sensing system and method for sensing exhaust emissions from motor vehicles is provided where the system determines the opacity of an exhaust plume. The system comprises a radiation source that emits radiation which is passed through the exhaust plume of a motor vehicle to one or more detectors arranged to receive the radiation. Multiple wavelength opacity measuring embodiments and monochromatic wavelength opacity measuring embodiments are disclosed.

Abstract: A remote emissions sensing system and method for sensing exhaust emissions from motor vehicles is provided where the system determines the opacity of an exhaust plume. The system comprises a radiation source that emits radiation which is passed through the exhaust plume of a motor vehicle to one or more detectors arranged to receive the radiation. Multiple wavelength opacity measuring embodiments and monochromatic wavelength opacity measuring embodiments are disclosed.

Abstract: A remote emissions sensing system and method for sensing exhaust emissions from motor vehicles is provided where the system determines the opacity of an exhaust plume. The system comprises a radiation source that emits radiation which is passed through the exhaust plume of a motor vehicle to one or more detectors arranged to receive the radiation. Multiple wavelength opacity measuring embodiments and monochromatic wavelength opacity measuring embodiments are disclosed.

Abstract: A remote emissions sensing system and method for sensing exhaust emissions from motor vehicles is provided where the system determines the opacity of an exhaust plume. The system comprises a radiation source that emits radiation which is passed through the exhaust plume of a motor vehicle to one or more detectors arranged to receive the radiation. Multiple wavelength opacity measuring embodiments and monochromatic wavelength opacity measuring embodiments are disclosed.

Abstract: A remote emissions sensing system and method for sensing exhaust emissions from motor vehicles is provided where the system determines the opacity of an exhaust plume. The system comprises a radiation source that emits radiation which is passed through the exhaust plume of a motor vehicle to one or more detectors arranged to receive the radiation. A processor calculates the difference between the intensity of source radiation and the intensity of the radiation received by the detectors in first and second detection bands. The intensity difference in the second detection band measures exhaust opacity. If the exhaust opacity exceeds a predetermined level, the emissions data from other detection bands may be flagged as suspect or discarded. Alternatively, for a diesel powered vehicle, the exhaust opacity determination can be validated by a measurement of carbon monoxide in the exhaust plume.

Abstract: A remote sensing device is provided to detect the emissions of passing vehicles. Preferably, the device detects the emissions of individual vehicles traveling on a roadway of more than one traffic lane. The remote sensing device may preferably detect the emissions due to an individual vehicle in situations where more than one vehicle is present. The device is capable of determining which sensed emission data corresponds to which vehicle exhaust plume.

Abstract: A remote emissions sensing system and method for sensing exhaust emissions from motor vehicles is provided where the system determines the opacity of an exhaust plume. The system comprises a radiation source that emits radiation which is passed through the exhaust plume of a motor vehicle to one or more detectors arranged to receive the radiation. A processor calculates the difference between the intensity of source radiation and the intensity of the radiation received by the detectors in first and second detection bands. The intensity difference in the second detection band measures exhaust opacity. If the exhaust opacity exceeds a predetermined level, the emissions data from other detection bands may be flagged as suspect or discarded. Alternatively, for a diesel powered vehicle, the exhaust opacity determination can be validated by a measurement of carbon monoxide in the exhaust plume.

Abstract: A system for remote analysis of vehicle emissions also determines whether each vehicle's engine and exhaust system are hot or cold by measuring infrared radiation reflected by the roadway beneath the vehicle. A source transmits a beam of radiation through at least a portion of the motor vehicle exhaust to a number of sensors. Each sensor generates a signal indicative of the absorption of the beam in a wavelength band indicative of a corresponding exhaust gas (e.g., CO, CO.sub.2, HC, NO.sub.x and H.sub.2 O). An infrared detector measures infrared radiation within a field of view including at least a portion of the roadway beneath each passing vehicle. A processor then computes the concentrations of each exhaust gas from the sensor signals, and determines whether the vehicle is hot or cold by measuring the intensity of infrared radiation detected by the infrared detector.

Abstract: A gas analysis device (10) for the remote detecting, measuring and recording of NO.sub.x, CO, CO.sub.2, HC and H.sub.2 O levels from the exhaust (30) of moving motor vehicles (28) utilizes a source (11) of collimated infrared and ultraviolet radiation (15) and includes a detector unit (16) positioned on the opposite side of the roadway for receiving and measuring the infrared and ultraviolet radiation from the source (11) tranmitted through the vehicle exhaust. The detector unit splits the combined infrared and ultraviolet radiation into separate infrared and ultraviolet beams (42) and (40). An ultraviolet sensor (44) receives the separate ultraviolet beam and generates a signal indicative of NO.sub.x. A rotating reflector (27) time-multiplexes the infrared beam to a plurality of infrared sensors that generate electrical signals indicative of, for example, CO, CO.sub.2, HC and H.sub.2 O in the vehicle exhaust. A computer (17) then computes the relative concentrations of CO, CO.sub.2, HC, NO.sub.x, and H.sub.