Patents by Inventor Carl A. Listl
Carl A. Listl 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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Patent number: 8212203Abstract: A radiation dosimetry method and associated devices for carrying out the method are disclosed herein. More particularly, a method and associated apparatus which compensates for variations in amounts of a radiation sensitive material in a radiation dosimetry film is provided.Type: GrantFiled: February 22, 2010Date of Patent: July 3, 2012Assignee: ISP Investments Inc.Inventors: David F. Lewis, Carl A. Listl, Xiang Yu
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Publication number: 20100213362Abstract: A radiation dosimetry method and associated devices for carrying out the method are disclosed herein. More particularly, a method and associated apparatus which compensates for variations in amounts of a radiation sensitive material in a radiation dosimetry film is provided.Type: ApplicationFiled: February 22, 2010Publication date: August 26, 2010Applicant: ISP INVESTMENTS INC.Inventors: David F. Lewis, Carl A. Listl, Xiang Yu
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Patent number: 7482601Abstract: An article of manufacture comprising a radiation sensitive material, and a measuring scale that is part of the radiation sensitive material. A method of measuring at least one parameter relating to an irradiated material is also described. A radiation sensitive material including a measuring scale is exposed to radiation and at least one parameter relating to one or more exposed areas of the material is measured by reference to the measuring scale on the material.Type: GrantFiled: November 17, 2005Date of Patent: January 27, 2009Assignee: ISP Investments Inc.Inventors: David F. Lewis, Carl A. Listl, Xiang Yu
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Publication number: 20070019790Abstract: An article of manufacture comprising a radiation sensitive material, and a measuring scale that is part of the radiation sensitive material. A method of measuring at least one parameter relating to an irradiated material is also described. A radiation sensitive material including a measuring scale is exposed to radiation and at least one parameter relating to one or more exposed areas of the material is measured by reference to the measuring scale on the material.Type: ApplicationFiled: November 17, 2005Publication date: January 25, 2007Inventors: David Lewis, Carl Listl, Xiang Yu
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Publication number: 20030129080Abstract: An item of mail or other container having an irradiation target area containing a radiochromic polyacetylene monomer indicia which is substantially stable to incident light, humidity and ambient temperatures and which develops a darkened color phase alteration at a level of radiation exposure sufficient to deactivate a bio-hazardous agent and a method of applying said radiochromic polyacetylene to a package or container.Type: ApplicationFiled: November 15, 2002Publication date: July 10, 2003Applicant: ISP INVESTMENTS INC.Inventors: David F. Lewis, J. Michael Donahue, Carl A. Listl, Xiang Yu
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Patent number: 6285031Abstract: A method and associated apparatus for monitoring exposure to radiation, with compensation for temperature variation of a sensor and variations in the amount of radiation sensitive material in a dosimeter used in the method. The method utilizes a radiation dosimeter having a layer of radiation sensitive material on a substrate, the radiation sensitive material having an optical absorbance which varies in accordance with degree of radiation exposure and wavelength and which also varies in dependence on temperature. The radiation sensitive layer includes a substantially radiation impervious substance.Type: GrantFiled: December 18, 1998Date of Patent: September 4, 2001Assignee: ISP Investments Inc.Inventors: Carl A. Listl, David F. Lewis
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Patent number: 6268602Abstract: In a method for manufacturing a calibrated radiation dosimeter, a layer of radiation sensitive material is applied to a substrate, the radiation sensitive material having an optical density which varies in accordance with a degree of radiation exposure. A pre-exposure optical density of the layer of radiation sensitive material is optically measured and subsequently the layer of radiation sensitive material is exposed to a known dose of radiation. Thereafter, a post-exposure optical density of the layer of radiation sensitive material is optically measured. Using at least the pre-exposure optical density, the post-exposure optical density, and the known dose of radiation, one computes mathematical parameters defining a predetermined mathematical function. The computed mathematical parameters are applied in encoded form to the substrate (e.g., printed in bar code form on the substrate or a holder card).Type: GrantFiled: January 27, 1998Date of Patent: July 31, 2001Assignee: ISP Investments Inc.Inventors: Henry Seiwatz, Carl A. Listl, J. Michael Donahue, David F. Lewis
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Patent number: 5777341Abstract: In a method for manufacturing a calibrated radiation dosimeter, a layer of radiation sensitive material is applied to a substrate, the radiation sensitive material having an optical density which varies in accordance with a degree of radiation exposure. A pre-exposure optical density of the layer of radiation sensitive material is optically measured and subsequently the layer of radiation sensitive material is exposed to a known dose of radiation. Thereafter, a post-exposure optical density of the layer of radiation sensitive material is optically measured. Using at least the pre-exposure optical density, the post-exposure optical density, and the known dose of radiation, one computes mathematical parameters defining a predetermined mathematical function. The computed mathematical parameters are applied in encoded form to the substrate (e.g., printed in bar code form on the substrate or a holder card).Type: GrantFiled: April 30, 1996Date of Patent: July 7, 1998Assignee: ISP Investments Inc.Inventors: Henry Seiwatz, Carl A. Listl, J. Michael Donahue, David F. Lewis
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Patent number: 5767520Abstract: A method for determining a level of exposure to radiation utilizes a radiation dosimeter comprising a substrate provided with a radiation sensitive layer or patch having an optical density which varies in accordance with the degree of radiation exposure. In addition, the substrate is provided with optically readable coding which identifies one or more encoded mathematical parameters for enabling an automated calculation of dosage from a detected optical density change of the radiation sensitive material. In the method, the coding on the dosimeter substrate is scanned to automatically determine the encoded mathematical parameters, and a plurality of pre-exposure optical densities and a plurality of post-exposure optical densities of the layer of radiation sensitive material in a plurality of wavelength bands are optically measured.Type: GrantFiled: November 25, 1996Date of Patent: June 16, 1998Assignee: ISP Investments Inc.Inventors: J. Michael Donahue, David F. Lewis, Henry Seiwatz, Carl A. Listl
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Patent number: 5637876Abstract: A method for determining a level of exposure to radiation utilizes a radiation dosimeter comprising a substrate provided with a radiation sensitive layer or patch having an optical density which varies in accordance with the degree of radiation exposure. In addition, the substrate is provided with optically readable coding which identifies encoded mathematical parameters for enabling an automated calculation of dosage from a detected post-exposure optical density of the radiation sensitive material. The method comprises the step of optically measuring the optical density of the layer of radiation sensitive material prior to exposure thereof to radiation. In addition, the coding on the dosimeter substrate is scanned to automatically determine the encoded mathematical parameters. The method further comprises the steps of exposing the radiation sensitive layer to radiation and optically measuring a post-exposure optical density of the layer of radiation sensitive material.Type: GrantFiled: November 7, 1995Date of Patent: June 10, 1997Assignee: ISP Investments Inc.Inventors: J. Michael Donahue, David F. Lewis, Henry Seiwatz, Carl A. Listl
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Patent number: 5084623Abstract: A multi-ply radiation dosage indicator, and method of manufacture, is disclosed including a first ply having visible indicia thereon and a second ply having a radiation sensitive zone overlying the indicia of the first ply. The radiation sensitive zone is capable of changing opacity in response to exposure to a radiation dosage exceeding a predetermined threshold so as to change the visibility of the indicia thereby providing an indication as to whether the indicator has become irradiated. An optical filter ply may be provided overlying the indicia, and the indicator also may be provided with a transparent protective outer ply. A pressure sensitive adhesive ply having a removable release sheet is employed for attaching the indicator to a substrate.Type: GrantFiled: February 7, 1991Date of Patent: January 28, 1992Assignee: ISP Investments Inc.Inventors: David F. Lewis, Carl A. Listl
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Patent number: 5051597Abstract: A multi-ply radiation dosage indicator, and method of manufacture, is disclosed including a first ply having visible indicia thereon and a second ply having a radiation sensitive zone overlying the indicia of the first ply. The radiation sensitive zone is capable of changing opacity in response to exposure to a radiation dosage exceeding a predetermined threshold so as to change the visibility of the indicia thereby providing an indication as to whether the indicator has become irradiated. An optical filter ply may be provided overlying the indicia, and the indicator also may be provided with a transparent protective outer ply. A pressure sensitive adhesive ply having a removable release sheet is employed for attaching the indicator to a substrate.Type: GrantFiled: February 9, 1990Date of Patent: September 24, 1991Assignee: GAF Chemicals CorporationInventors: David F. Lewis, Carl A. Listl, Mark L. Moskowitz, Anthony Pilato, Robert D. Schenfele
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Patent number: 4786806Abstract: A retarding field spectrometer has a mounting ring for attachment to the pole piece of a scanning electron microscope or similar beam generator. Supported by the mounting ring are three screen electrodes with their planes positioned normal to the beam axis and adjustable as a unit in a pseudo-orthogonal manner through two worm and gear drives of eccentrics cooperating with an aperture and a slot, respectively, in a plate carrying the electrode closest to the pole piece. Three continuous dynode electron multipliers are arrayed symmetrically about the beam at-rest axis between the last mentioned electrode and the intermediate electrode. The multipliers have cathodes maintained at substantially the same potential as the intermediate electrode.Type: GrantFiled: June 22, 1987Date of Patent: November 22, 1988Assignee: GAF CorporationInventors: Carl A. Listl, Henry Seiwatz