Device and method for measuring temperture of vehicle exhaust
First Claim
1. A system for measuring temperature and CO, CO2 and HC content of a vehicle exhaust comprising:
- means for intermittently projecting infrared electromagnetic radiation through a plume of vehicle exhaust; and
means for receiving the infrared electromagnetic radiation which has passed through the plume of vehicle exhaust and for receiving infrared electromagnetic radiation emitted by the exhaust plume during intervals when said means for intermittently projecting infrared electromagnetic radiation through a plume of vehicle exhaust does not project infrared electromagnetic radiation through the exhaust plume,means, responsive to the received infrared electromagnetic radiation, for detecting an intensity of predetermined wavelengths of electromagnetic radiation which are characteristics of absorption and emission spectra of CO, CO2 and HC gases; and
means for computing the temperature. CO, CO2, and HC content of the plume based on the detected intensities.
11 Assignments
0 Petitions
Accused Products
Abstract
A system (10) for simultaneously measuring temperature and CO, CO2 and HC gas content of vehicle (11) exhaust detects and analyzes a beam of infrared electromagnetic radiation (21) projected through a plume (13) of vehicle exhaust to assess the concentration of CO, CO2, and HC in the vehicle exhaust and detects and analyzes infrared electromagnetic radiation (15) emitted by the plume (13) to assess the temperature of the plume (13) and, consequently, whether the vehicle'"'"'s (11) catalytic converter is operating in the cold or hot mode. Essentially simultaneous measurement is taken by intermittently interrupting the beam (21) of projected infrared electromagnetic radiation and detecting and analyzing the emitted infrared radiation (15) during the intervals of interruption when the beam (21) is not projected through the plume (13). Intermittent projection of the beam (21) is accomplished by insertion of a chopper wheel (22) between an infrared beam projector (20) and the plume (13).
59 Citations
15 Claims
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1. A system for measuring temperature and CO, CO2 and HC content of a vehicle exhaust comprising:
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means for intermittently projecting infrared electromagnetic radiation through a plume of vehicle exhaust; and means for receiving the infrared electromagnetic radiation which has passed through the plume of vehicle exhaust and for receiving infrared electromagnetic radiation emitted by the exhaust plume during intervals when said means for intermittently projecting infrared electromagnetic radiation through a plume of vehicle exhaust does not project infrared electromagnetic radiation through the exhaust plume, means, responsive to the received infrared electromagnetic radiation, for detecting an intensity of predetermined wavelengths of electromagnetic radiation which are characteristics of absorption and emission spectra of CO, CO2 and HC gases; and means for computing the temperature. CO, CO2, and HC content of the plume based on the detected intensities. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A system for simultaneously measuring temperature and CO, CO2, and HC gas content of vehicle exhaust comprising:
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means for projecting a beam of infrared electromagnetic radiation through a plume of vehicle exhaust; a chopper wheel positioned between said means for projecting a beam of infrared electromagnetic radiation and the plume of vehicle exhaust, said chopper wheel being adapted for intermittently projecting the beam of infrared electromagnetic radiation through the plume of vehicle exhaust; first means for detecting intensities of wavelengths of infrared electromagnetic radiation characteristically absorbed from the beam of infrared electromagnetic radiation by CO present in the vehicle exhaust; second means for detecting intensities of wavelengths of infrared electromagnetic radiation characteristically absorbed from the beam of infrared electromagnetic radiation by CO2 present in the vehicle exhaust; third means for detecting intensities of wavelengths of infrared electromagnetic radiation characteristically absorbed from the beam of infrared electromagnetic radiation by hydrocarbons HC present in the vehicle exhaust; fourth means for detecting intensities of wavelengths of infrared electromagnetic radiation that are not characteristically absorbed from the beam of infrared electromagnetic radiation by CO, CO2, and HC present in the radiation vehicle exhaust; beam splitting means for directing the beam of infrared electromagnetic radiation after passing through the plume of vehicle exhaust and infrared electromagnetic radiation emitted by the plume of vehicle exhaust, to said first means for detecting intensities of wavelengths of infrared electromagnetic radiation, said second means for detecting intensities of wavelengths of infrared electromagnetic radiation, said third means for detecting intensities of wavelengths of infrared electromagnetic radiation, and said fourth means for detecting intensities of wavelengths of infrared electromagnetic radiation; means, responsive to detected intensities of wavelengths of infrared electromagnetic radiation output by said fourth means prior to projection of the beam of infrared electromagnetic radiation through the plume of vehicle exhaust, for determining a reference intensity value for normalizing the detected intensities of wavelengths of infrared electromagnetic radiation output from said first, second and third intensity detecting means; and means for computing the temperature, CO, CO2, and HC content of the plume based at least in part on the normalized detected intensities. - View Dependent Claims (8, 9, 10, 11)
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12. An apparatus for simultaneously measuring temperature and CO, CO2, and HC gas content of vehicle exhaust comprising:
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means for projecting infrared electromagnetic radiation through a plume of vehicle exhaust; means for receiving the infrared electromagnetic radiation which has passed through the plume of vehicle exhaust and for detecting an intensity of predetermined wavelengths of electromagnetic radiation which are characteristic of absorption spectra of CO, CO2, and HC; means for receiving infrared electromagnetic radiation emitted by the plume of vehicle exhaust and for detecting intensities of wavelengths of infrared electromagnetic radiation characteristically emitted by CO, CO2, and HC present in the plume of vehicle exhaust at a predetermined temperature; and means for computing the temperature, CO, CO2, and HC content of the plume based on the detected intensities. - View Dependent Claims (13)
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14. A method for measuring a temperature of a vehicle exhaust that contains chemical species of interest, comprising the steps of:
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intermittently projecting a beam of IR radiation through a region; prior to the passage of a vehicle through the region, obtaining a first measurement of an absorption of the beam within the region, during a time that the beam is projected, and obtaining a second measurement of an emission of IR radiation from within the region, during a time that the beam is not projected; after the passage of a vehicle through the region, obtaining a third measurement, during a time that the beam is projected, of an absorption of the beam within the vehicle'"'"'s exhaust by at least one chemical species of interest, and obtaining a fourth measurement, during a time that the beam is not projected, of an emission of IR radiation from within the vehicle'"'"'s exhaust by the least one chemical species of interest; determining a concentration of the at least one chemical species of interest in accordance with the first and third measurements; and determining a temperature of the vehicle'"'"'s exhaust in accordance with the determined concentration and in accordance with the second and fourth measurements.
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15. A system for measuring a temperature of a vehicle exhaust that contains chemical species of interest, comprising:
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means for intermittently projecting a beam of IR radiation through a region; a plurality of spectrally selective IR radiation detection components disposed in a path of said beam; and measurement means having inputs coupled to outputs of said plurality of spectrally selective IR radiation detection components, said measurement means being response to a time prior to a passage of a vehicle through the region for obtaining a first measurement of an absorption of the beam within the region, during a time that the beam is projected, and for obtaining a second measurement of an emission of IR radiation from within the region, during a time that the beam is not projected, said measurement means being further responsive to a time after the passage of the vehicle through the region for obtaining a third measurement, during a time that the beam is projected, of an absorption of the beam within the vehicle'"'"'s exhaust by at least one chemical species of interest, and for obtaining a fourth measurement, during a time that the beam is not projected, of an emission of IR radiation from within the vehicle'"'"'s exhaust by the least one chemical species of interest;
wherein said measurement means includes means for determining a concentration of the at least one chemical species of interest in accordance with the first and third measurements and for determining a temperature of the vehicle'"'"'s exhaust in accordance with the determined concentration and in accordance with the second and fourth measurements.
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Specification