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. 06, 1990
Filed:
Mar. 20, 1989
Raymond D Rempt, Woodinville, WA (US);
The Boeing Company, Seattle, WA (US);
Abstract
A fiber-optic magnetic field gradiometer uses a plurality of magnetic transducers to simultaneously determine multicomponents of the gradient and field strength of an external magnetic field so as to permit accurate determination of the location of a ferromagnetic object located in an array of objects. The magnetic transducers are made of several layers of magnetostrictive glass which 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. The nulling technique may be accomplished in real time and does not require cutting off the drive signals to adjacent coils. Thus the nulling may be accomplished simultaneously for all coils as the balancing of each coil is independent of its neighbors. A magnetic field to be detected along the axes of the magnetic transducers causes an optical path length change in the fibers. By employing eight magnetic transducers, all gradients and fields may be determined at the same time. Further by employing additional transducers, for a total of thirteen, the second derivatives of the fields may also be determined.