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:
Mar. 21, 1989
Filed:
Mar. 18, 1988
Raymond D Rempt, Woodinville, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
A fiber-optic magnetic field gradiometer uses the second derivative of a magnetic field to determine the location of a ferromagnetic object located in an array of objects. Three adjacent magnetic transducers made of several layers of magnetostrictive glass are wrapped with an optical fiber and immersed in an applied magnetic field to null out material differences and the earth's magnetic field. The null conditions for each adjacent pair are accomplished without disturbing the null conditions of the other adjacent pair. A magnetic field to be detected along the axes of the magnetic transducers causes an optical path length change in the fibers. The overall path length change is proportional to the second derivative of the magnetic field.