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:
Aug. 14, 2001
Filed:
Nov. 29, 1999
Frank H. Born, Westernville, NY (US);
John E. Dodge, Annandale, VA (US);
William G. Duff, Fairfax Station, VA (US);
Laurence J. Reynolds, Manassas, VA (US);
Arlie G. Turner, Jr., Annandale, VA (US);
The United States of America as represented by the Secretary of the Air Force, Washington, DC (US);
Abstract
Apparatus and method to detect corrosion in metal junctions. Corroded metal junctions are usually discovered by visual inspection. The present invention detects corrosion in metal junctions when it is not visually apparent. A corroded metal junction acts as a nonlinear device. It generates harmonics and other nonlinear products (such as intermodulation) of any signals applied to the junction. The presence of relatively high level harmonics and/or intermodulation products indicates directly that corrosion has occurred. To detect corrosion in a metal junction, one couples a fundamental frequency signal (f,) into the junction and tests for harmonics of that frequency, especially the third harmonic. Harmonic frequency signals that are relatively large (i.e., above the harmonics generated by the testing system) indicate the presence of corrosion. Measurements to determine if a metal junction is corroded are performed without disturbing the junction.