Patents by Inventor Donald H. Stedman
Donald H. Stedman has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20030120434Abstract: 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.Type: ApplicationFiled: October 28, 2002Publication date: June 26, 2003Inventors: John DiDomenico, James H. Johnson, Donald H. Stedman, Gary A. Bishop, Craig S. Rendahl
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Publication number: 20020092988Abstract: 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.Type: ApplicationFiled: July 18, 2001Publication date: July 18, 2002Inventors: John Didomenico, James H. Johnson, Donald H. Stedman, Gary A. Bishop, W. John Williams
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Publication number: 20020052698Abstract: 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.Type: ApplicationFiled: March 28, 2001Publication date: May 2, 2002Inventors: John Didomenico, James H. Johnson, Donald H. Stedman, Gary A. Bishop, Craig S. Rendahl
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Patent number: 5935519Abstract: A process and apparatus are disclosed for the detection and measurement of sulfur in both organic and inorganic sulfur-containing compounds. The process includes admixing a sample including a sulfur-containing compound with oxygen, and then exposing the mixture to a source of combustion causing heat in the presence of a combustion supporting reducing agent at a combustion site. The resulting gaseous combustion products are vacuum extracted from the combustion site, and then directed into a darkened low pressure chamber. The combustion products in the low pressure chamber are then contacted with ozone, with the result that the sulfur combustion products are converted to chemiluminescent sulfur dioxide. The emitted chemiluminescence is then detected, and may be measured to provide a quantitative indication of the amount of sulfur in the original sample. The preferred source of oxygen is air, the preferred form of combustion heat is a flame, and the preferred form of reducing agent is hydrogen gas.Type: GrantFiled: May 23, 1997Date of Patent: August 10, 1999Assignee: Sievers Instruments, Inc.Inventors: Richard L. Benner, Donald H. Stedman
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Patent number: 5702954Abstract: An apparatus to detect and measure the amount of phosphorus in phosphorus-containing compounds comprises a burning chamber with a housing having an integral combustion chamber. A flammable reducing agent such as hydrogen is introduced into the combustion chamber along with a sample containing phosphorus admixed with air or oxygen. At least a portion of any phosphorus in the sample will be converted into phosphorus monoxide (PO) by the combustion. The resulting phosphorus monoxide is immediately drawn into a low-pressure, ambient temperature reaction chamber and reacted with ozone to convert the phosphorus monoxide to chemiluminescent phosphorus dioxide. A light-measuring device then measures the intensity of the light released from the chemiluminescent phosphorus dioxide.Type: GrantFiled: September 29, 1995Date of Patent: December 30, 1997Assignee: Colorado SeminaryInventors: Donald H. Stedman, Patti A. Meeks
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Patent number: 5661036Abstract: A process and apparatus are disclosed for the detection and measurement of sulfur in both organic and inorganic sulfur-containing compounds. The process includes admixing a sample including a sulfur-containing compound with oxygen, and then exposing the mixture to a source of combustion causing heat in the presence of a combustion supporting reducing agent at a combustion site. The resulting gaseous combustion products are vacuum extracted from the combustion site, and then directed into a darkened low pressure chamber. The combustion products in the low pressure chamber are then contacted with ozone, with the result that the sulfur combustion products are converted to chemiluminescent sulfur dioxide. The emitted chemiluminescence is then detected, and may be measured to provide a quantitative indication of the amount of sulfur in the original sample. The preferred source of oxygen is air, the preferred form of combustion heat is a flame, and the preferred form of reducing agent is hydrogen gas.Type: GrantFiled: May 16, 1995Date of Patent: August 26, 1997Assignee: Sievers Instruments, Inc.Inventors: Richard L. Benner, Donald H. Stedman
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Patent number: 5498872Abstract: A gas analysis device for the remote detecting, measuring and recording of NO, 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). The ultraviolet beam is diffracted onto a photodiode array in a spectrometer that generates a signal indicative of NO in the vehicle exhaust. 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.Type: GrantFiled: April 21, 1995Date of Patent: March 12, 1996Assignee: Colorado SeminaryInventors: Donald H. Stedman, Gary Bishop, Scott McLaren
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Patent number: 5489777Abstract: 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.Type: GrantFiled: March 3, 1995Date of Patent: February 6, 1996Assignee: Denver SeminaryInventors: Donald H. Stedman, Gary A. Bishop
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Patent number: 5424217Abstract: A process and apparatus are disclosed for the detection and measurement of sulfur in both organic and inorganic sulfur-containing compounds. The process includes admixing a sample including a sulfur-containing compound with oxygen, and then exposing the mixture to a source of combustion causing heat in the presence of a combustion supporting reducing agent at a combustion site. The resulting gaseous combustion products are vacuum extracted from the combustion site, and then directed into a darkened low pressure chamber. The combustion products in the low pressure chamber are then contacted with ozone, with the result that the sulfur combustion products are converted to chemiluminescent sulfur dioxide. The emitted chemiluminescence is then detected, and may be measured to provide a quantitative indication of the amount of sulfur in the original sample. The preferred source of oxygen is air, the preferred form of combustion heat is a flame, and the preferred form of reducing agent is hydrogen gas.Type: GrantFiled: April 24, 1992Date of Patent: June 13, 1995Assignee: Sievers Instruments, Inc.Inventors: Richard L. Benner, Donald H. Stedman
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Patent number: 5401967Abstract: A gas analysis device for the remote detecting, measuring and recording of NO, 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). The ultraviolet beam is diffracted onto a photodiode array in a spectrometer that generates a signal indicative of NO in the vehicle exhaust. 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.Type: GrantFiled: June 3, 1994Date of Patent: March 28, 1995Assignee: Colorado Seminary dba University of DenverInventors: Donald H. Stedman, Gary Bishop, Scott McLaren
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Patent number: 5371367Abstract: Apparatus for detecting and measuring relative concentrations of pollutants such as HC, CO and CO.sub.2 in the exhaust emissions from passing vehicles includes an infrared (IR) beam source for directing an IR beam through a vehicle's exhaust plume and a detector disposed on one side of a roadway and a lateral transfer mirror (LTM) disposed on the other side of the roadway for lateral reflecting of the IR beam back through the vehicle's exhaust plume and onto the detector. The LTM allows for close spacing and precise alignment between the emitted and reflected beam paths and permits the IR beam source and detector to be disposed in a single module. Compensation for variation in a range of vehicle operating conditions is provided by adjustable, computer-controlled potentiometers, while audio and/or visible light feedback of the detected IR signal allows a single operator to precisely align the optical components of the apparatus.Type: GrantFiled: April 13, 1993Date of Patent: December 6, 1994Assignees: Envirotest Systems Corp., Colorado SeminaryInventors: John DiDomenico, James H. Johnson, Kenneth W. Michaels, Donald H. Stedman, Dennis L. Smith
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Patent number: 5330714Abstract: The present invention describes the process and apparatus for the simultaneous measurement of sulfur-containing compounds and organic compounds with or without sulfur in their structures. A detector cell is described that allows simultaneous measurement of compounds that can be ionized in a flame and thereby cause the electrical conductivity of the flame to increase, and the selective measurement of sulfur-containing compounds which simultaneously form sulfur monoxide. Sulfur monoxide, upon mixing with ozone, emits light from 240 to 450 nm. The intensity of the light can be measured and related to the concentration of sulfur in the sample, while changes in electrical conductivity of the flame measured by imposing a voltage across the cell quantifies the organic compounds irrespective of whether or not they contain sulfur.Type: GrantFiled: February 4, 1993Date of Patent: July 19, 1994Assignee: Sievers Instruments, Inc.Inventors: Richard Godec, Neil Johansen, Donald H. Stedman
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Patent number: 5319199Abstract: 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.Type: GrantFiled: June 8, 1992Date of Patent: June 7, 1994Assignee: Colorado SeminaryInventors: Donald H. Stedman, Gary A. Bishop
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Patent number: 5310683Abstract: A process and apparatus for the simultaneous measurement of sulfur-containing compounds and organic compounds with or without sulfur in their structures. A detector cell allows simultaneous measurement of compounds that can be ionized in a flame and thereby cause the electrical conductivity of the flame to increase, and the selective measurement of sulfur-containing compounds which simultaneously form sulfur monoxide. Sulfur monoxide, upon mixing with ozone, emits light from 240 to 450 nm. The intensity of the light can be measured and related to the concentration of sulfur in the sample, while changes in electrical conductivity of the flame measured by imposing a voltage across the cell quantifies the organic compounds irrespective of whether or not they contain sulfur.Type: GrantFiled: September 6, 1991Date of Patent: May 10, 1994Assignee: Sievers Research, Inc.Inventors: Richard Godec, Neil Johansen, Donald H. Stedman
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Patent number: 5227135Abstract: The present invention describes the process and apparatus for the simultaneous measurement of sulfur-containing compounds and organic compounds with or without sulfur in their structures. A detector cell is described that allows simultaneous measurement of compounds that can be ionized in a flame and thereby cause the electrical conductivity of the flame to increase, and the selective measurement of sulfur-containing compounds which simultaneously form sulfur monoxide. Sulfur monoxide, upon mixing with ozone, emits light from 240 to 450 nm. The intensity of the light can be measured and related to the concentration of sulfur in the sample, while changes in electrical conductivity of the flame measured by imposing a voltage across the cell quantifies the organic compounds irrespective of whether or not they contain sulfur.Type: GrantFiled: September 6, 1991Date of Patent: July 13, 1993Assignee: Sievers Research, Inc.Inventors: Richard Godec, Neil Johansen, Donald H. Stedman
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Patent number: 5210702Abstract: A gas analysis device 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 of moving motor vehicles. It utilizes a source of collimated infrared and ultraviolet radiation and includes a mechanism for receiving and measuring the infrared and ultraviolet radiation from its source, and another mechanism for measuring background infrared and ultraviolet radiation levels in the ambient atmosphere. The receiving mechanism splits the combined infrared and ultraviolet radiation into separate infrared and ultraviolet beams. A mechanism receives the separate ultraviolet beam and generates a signal indicative of NO.sub.x. Another mechanism splits the infrared beam into two to four components, and devices are positioned for receiving each of the infrared components and generating two to four signals indicative of, for example, CO, CO.sub.2, HC and H.sub.2 O. Another associated mechanism then computes and produces signals indicative of the amount of CO, CO.Type: GrantFiled: December 26, 1990Date of Patent: May 11, 1993Assignee: Colorado SeminaryInventors: Gary Bishop, Donald H. Stedman
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Patent number: 5070246Abstract: A device and method for measuring the concentrations of components of a fluid stream. Preferably, the fluid stream is an in situ gas stream, such as a fossil fuel fired flue gas in a smoke stack. The measurements are determined from the intensity of radiation over a selected range of radiation wavelengths using peak-to-trough calculations. The need for a reference intensity is eliminated.Type: GrantFiled: September 22, 1989Date of Patent: December 3, 1991Assignee: ADA Technologies, Inc.Inventors: Michael D. Durham, Donald H. Stedman, Timothy G. Ebner, Mark R. Burkhardt
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Patent number: 4765961Abstract: Chemiluminescence is detected in a luminol solution free of metal ions flowing through a porous material to indicate the presence of certain nitrogen-containing gases. Continuous monitoring of atmosphoric gases is possible through use of the described methods and related apparatus.Type: GrantFiled: April 30, 1984Date of Patent: August 23, 1988Assignees: The University of Michigan, Scintrex LimitedInventors: Harold I. Schiff, Donald H. Stedman
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Patent number: 4678488Abstract: A liquid separator for a gas analyzer is provided comprising a sample gas inlet; a sample gas outlet; and a separation chamber in fluid communication with the gas inlet and gas outlet. The separation chamber is provided with a smooth, planar upper wall and a smooth planar lower wall, the upper and lower walls being substantially parallel and having a small uniform clearance therebetween. A motor is provided for rotating the lower wall of the separation chamber about a central axis normal to the surfaces of the upper and lower walls. The gas outlet is disposed on the central axis of the rotating lower wall. The gas inlet is disposed off of the central axis. A vacuum is applied to the sample gas outlet to draw sample gas through the separation chamber. A collection chamber is provided which surrounds the separation chamber for receiving liquids and other debris separated from the sample gas flow by contact with the rotating lower wall and centrifugal acceleration imparted thereto by the lower wall.Type: GrantFiled: May 2, 1985Date of Patent: July 7, 1987Assignee: Sensors, Inc.Inventors: Charles P. Howard, Donald H. Stedman
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Patent number: 4205956Abstract: A sensitive portable detector for nickel carbonyl is provided which relies on chemiluminescence produced in the presence of ozone and carbon monoxide by pulse-modulating the carbon monoxide feed to the reactor chamber and detecting the resulting modulation of the output signal. The instrument is thus made insensitive to any NO which may be present in the gas sample.Type: GrantFiled: May 21, 1979Date of Patent: June 3, 1980Assignee: The International Nickel Company, Inc.Inventor: Donald H. Stedman