The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 02, 1992
Filed:
Jun. 03, 1991
Applicant:
Inventors:
David E Kranbuehl, Williamsburg, VA (US);
Robert L Fox, Hayes, VA (US);
Assignee:
Center for Innovative Technology, Herndon, VA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G01N / ; G01R / ; G01R / ;
U.S. Cl.
CPC ...
324234 ; 324236 ; 324655 ;
Abstract
An L-C circuit (tank circuit) is located in close proximity to polymer impregnated composite material layers during the fabrication process. Applicant has determined that the resonant frequency of the tank circuit and the shape of the frequency absorption curve vary as a function of the fiber density of polymer impregnated composite material. The frequency of the input to the tank circuit is periodically swept through a range of frequencies, and the tank circuit impedance is measured to determine the resonant frequency and shape of the frequency absorption curve.