Accession Number : ADD007201

Title :   Method and Apparatus for Reducing Magnetometer Errors.

Descriptive Note : Patent,


Personal Author(s) : Obenschain,Arthur W

Report Date : 18 Mar 1980

Pagination or Media Count : 7

Abstract : This invention relates to magnetometers and more particularly to a method and apparatus for reducing errors as a result of turnover and block misparabolism during the manufacture of a total field magnetometer. A total field magnetometer of the type contemplated by the present invention consists of three pairs of magnetometer elements arranged in three mutually perpendicular planes. Each of these magnetometer elements consists of a coil centered on a low retentivity magnetic core of high permeability. A suitable value of alternating current is applied to the coils in series. The reduction in inductance (reductance) of each coil from its value in zero magnetic field is proportional to the square of the field strength along its axis. Since the axes of the three pairs of coils are mutually perpendicular, the total inductance of the coils will be constant ideally regardless of the position in which the magnetometer is placed with respect to an external constant magnetic field. Stated differently, the total inductance of the magnetometer, regardless of its orientation in a magnetic field, is proportional to the sum of the squares of the three field components, and this sum is the square of the magnetic field strength sensed by the magnetometer. A perfect total field magnetometer thus can be subjected to any and all motions both translatory and rotative in a magnetic field of constant magnitude and its inductance will remain unchanged.

Descriptors :   *Patents, *Magnetometers, Errors, Compensation, Magnetic fields, Inductance, Test methods

Subject Categories : Magnetic & Electric Fld Detection & Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE