Accession Number : ADD012450

Title :   Fiber Optic DC Magnetometer without Hysteresis Ambiguity.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Koo,Kee P ; Sigel,George H , Jr

Report Date : 29 Jul 1986

Pagination or Media Count : 8

Abstract : This patent discloses a fiber optic magnetometer for detecting DC magnetic fields includes a first optical fiber having a magnetostrictive jacket thereon which defines a sensing arm, and a second fiber defining a reference arm. A first AC magnetic field of frequency and a second AC field of frequency are imposed on the magnetostrictive jacket so as to cause a time varying optical path length change. The sum of the components changes in magnitude upon exposure of the magnetostrictive jacket of a DC field, thereby indicating the presence of a DC field, thereby indicating the presence of a DC field. The lock-in amplifier output is plotted on an oscilloscope versus the second AC field of frequency was to give a loop which shifts in position when the device is exposed to an external DC field.

Descriptors :   *PATENTS, *MAGNETOMETERS, *FIBER OPTICS, INTERFEROMETERS, MAGNETOSTRICTION, MAGNETIC FIELDS, DIRECT CURRENT, HYSTERESIS

Subject Categories : Test Facilities, Equipment and Methods
      Magnetic & Electric Fld Detection & Detectors
      Fiber Optics and Integrated Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE