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:
Jan. 19, 1993
Filed:
Feb. 04, 1992
Hegeon Kwun, San Antonio, TX (US);
Gary L Burkhardt, Adkins, TX (US);
Jay L Fisher, San Antonio, TX (US);
Southwest Research Institute, San Antonio, TX (US);
Abstract
A method for rapidly detecting and locating reinforcing steel corrosion in concrete structures using non-linear harmonic and intermodulated frequencies of electromagnetic signals. The method comprises transmitting either a single primary frequency or two primary frequencies into the concrete structure in the general direction of the reinforcing steel. The reflected/generated signal, which is composed of the primary frequencies and of various harmonics and intermodulation components, is received, filtered, and amplified. A third order harmonic frequency is isolated with a band pass filter, is amplified, and is compared with the amplitudes of the primary frequencies. Intermodulation frequencies, primarily the combination of the primary of a frequency and the second harmonic of a second frequency, or the primary of a second frequency and the second harmonic of a first frequency, are isolated by appropriate band pass filter, are amplified, and are compared with the primary frequency or frequencies. The comparative amplitudes of these harmonics or intermodulation frequencies are displayed and recorded, and are correlated with a degree of corrosion in the reinforcing steel.