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:
Dec. 15, 1992
Filed:
Dec. 12, 1991
Jean-Pierre Tasca, Sainte Genevieve Des Bois, FR;
Compagnie Generale d'Automatisme CGA-HBS, Bretigny Sur Orge, FR;
Abstract
An embodiment comprises a generator constituted by a quartz crystal oscillator and programmable frequency dividers; a power amplifier providing a periodic excitation signal, of squarewave form; two coils electromagnetically coupled to a metal part to be tested; and measuring means comprising two synchronous detectors for measuring the real part and the imaginary part of the difference between the complex impedances of the coils. The frequency stability of the generator effects an improvement in the accuracy of the impedance measurements, when these measurements are made at different frequencies. For application to non-destructive testing of metal parts by eddy currents, at different frequencies.