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:
Jul. 14, 1992
Filed:
Jun. 16, 1989
Marc D Mermelstein, Chevy Chase, MD (US);
University of Virginia Alumni Patents Foundation, Charlottesville, VA (US);
Abstract
A single magnetostrictive amorphous metal sensor element is mounted on a piezoelectric resonator plate with an intervening layer of a viscous fluid, an oscillator stresses and vibrates the plate at a resonant frequency, creating a standing wave in the sensor element which is a metallic glass ribbon. Electromotive forces are generated in first and second pickup coils mounted at symmetrically spaced positions about the ribbon centerline. The electromotive force generated by each pickup coil is demodulated by a lock-in amplifier with a signal supplied by the oscillator. The demodulated outputs are amplified so as to balance the sensitivities. Outputs of amplifiers are provided to a differential amplifier which produces the gradiometer output indicative of magnetic field gradient.