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:
Aug. 13, 1991
Filed:
May. 08, 1990
Robert J Weber, Boone, IA (US);
Wing C Chung, Ames, IA (US);
David C Jiles, Ames, IA (US);
John D Verhoeven, Ames, IA (US);
Iowa State University Research Foundation, Inc., Ames, IA (US);
Abstract
A magnetometer which employs a rod of magnetostrictive material comprising a ternary alloy of dysprosium, terbium and iron wherein the grains of the material have their common principal axes substantially pointed along the axis of the rod. Means are provided for compressively stressing the rod in order to enhance the magnetostrictive response thereof. A laser source and photosensor are associated with a free end of the rod to function as an external cavity laser sensor. A DC magnetic bias is required for the magnetostrictive rod in order to operate in the sensitive range of the magnetostrictive characteristics of the rod. In a portable implementation of the device, the DC bias is provided by means of permanent magnets, preferably rare earth magnets, in order to provide the high bias fields compatible with high sensitivity of the material in a miniaturized portable device.