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).

  • Patent number: 8212203
    Abstract: 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: Grant
    Filed: February 22, 2010
    Date of Patent: July 3, 2012
    Assignee: ISP Investments Inc.
    Inventors: David F. Lewis, Carl A. Listl, Xiang Yu
  • Publication number: 20100213362
    Abstract: 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: Application
    Filed: February 22, 2010
    Publication date: August 26, 2010
    Applicant: ISP INVESTMENTS INC.
    Inventors: David F. Lewis, Carl A. Listl, Xiang Yu
  • Patent number: 7482601
    Abstract: 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: Grant
    Filed: November 17, 2005
    Date of Patent: January 27, 2009
    Assignee: ISP Investments Inc.
    Inventors: David F. Lewis, Carl A. Listl, Xiang Yu
  • Publication number: 20070019790
    Abstract: 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: Application
    Filed: November 17, 2005
    Publication date: January 25, 2007
    Inventors: David Lewis, Carl Listl, Xiang Yu
  • Publication number: 20030129080
    Abstract: 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: Application
    Filed: November 15, 2002
    Publication date: July 10, 2003
    Applicant: ISP INVESTMENTS INC.
    Inventors: David F. Lewis, J. Michael Donahue, Carl A. Listl, Xiang Yu
  • Patent number: 6285031
    Abstract: 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: Grant
    Filed: December 18, 1998
    Date of Patent: September 4, 2001
    Assignee: ISP Investments Inc.
    Inventors: Carl A. Listl, David F. Lewis
  • Patent number: 6268602
    Abstract: 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: Grant
    Filed: January 27, 1998
    Date of Patent: July 31, 2001
    Assignee: ISP Investments Inc.
    Inventors: Henry Seiwatz, Carl A. Listl, J. Michael Donahue, David F. Lewis
  • Patent number: 5777341
    Abstract: 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: Grant
    Filed: April 30, 1996
    Date of Patent: July 7, 1998
    Assignee: ISP Investments Inc.
    Inventors: Henry Seiwatz, Carl A. Listl, J. Michael Donahue, David F. Lewis
  • Patent number: 5767520
    Abstract: 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: Grant
    Filed: November 25, 1996
    Date of Patent: June 16, 1998
    Assignee: ISP Investments Inc.
    Inventors: J. Michael Donahue, David F. Lewis, Henry Seiwatz, Carl A. Listl
  • Patent number: 5637876
    Abstract: 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: Grant
    Filed: November 7, 1995
    Date of Patent: June 10, 1997
    Assignee: ISP Investments Inc.
    Inventors: J. Michael Donahue, David F. Lewis, Henry Seiwatz, Carl A. Listl
  • Patent number: 5084623
    Abstract: 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: Grant
    Filed: February 7, 1991
    Date of Patent: January 28, 1992
    Assignee: ISP Investments Inc.
    Inventors: David F. Lewis, Carl A. Listl
  • Patent number: 5051597
    Abstract: 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: Grant
    Filed: February 9, 1990
    Date of Patent: September 24, 1991
    Assignee: GAF Chemicals Corporation
    Inventors: David F. Lewis, Carl A. Listl, Mark L. Moskowitz, Anthony Pilato, Robert D. Schenfele
  • Patent number: 4786806
    Abstract: 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: Grant
    Filed: June 22, 1987
    Date of Patent: November 22, 1988
    Assignee: GAF Corporation
    Inventors: Carl A. Listl, Henry Seiwatz