Patents by Inventor Otto Kroggel

Otto Kroggel 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).

  • Method and apparatus for measuring diameter of a steel reinforcement rod embedded in concrete and the thickness of the concrete overlayer
    Patent number: 4837509
    Abstract: A method and apparatus for measuring the overlayer of a nonmagnetic mater such as concrete and the diameter of steel reinforcement bars embedded therein. A steady state magnetic flux field is generated in the area of the concrete which is to be tested. A reinforcement bar embedded within the concrete generates a scatter field which is superimposed on the excitation field. By scanning the concrete surface, an amplitude locus is determined which is subtracted from an amplitude locus determined in the absence of ferromagnetic objects, whereby a difference locus is obtained. The concrete overlayer and the diameter of the steel reinforcement bar are determined from the location and magnitude of the maximum values of the difference locus with the aid of an evaluation computer.
    Type: Grant
    Filed: September 30, 1986
    Date of Patent: June 6, 1989
    Assignee: Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung e.V.
    Inventors: Gerd Dodmann, Otto Kroggel, Jochen Fey, Harald Kopp, Christoph Fritz