Magnetism measurement device

Patent metadata

Field	Value
Publication number	US-10012705-B2
Application number	US-201414773633-A
Country	US
Kind code	B2
Filing date	Mar 7, 2014
Priority date	Mar 8, 2013
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

Magnetic-field measuring device having: elongate magnetic-material formed of solid or liquid having magnetic-anisotropy, or composite of solid and liquid; an electrically conductive-body adjacent to magnetic-material, giving magnetic-material a current-induced magnetic-field-vector having a component perpendicular to longitudinal-directions of magnetic-material; coil detecting magnetic-field by magnetic-material, which is magnetized in a direction perpendicular to its longitudinal-direction when no external magnetic-field is applied to magnetic-material or when only a magnetic-field not having a component in longitudinal-direction applied to magnetic-material, and magnetizing in direction having the component in longitudinal-direction when external magnetic-field have the component in longitudinal-direction of magnetic-material applied to magnetic-material, a direction of magnetization of magnetic-material aligned with direction perpendicular to longitudinal-direction of magnetic-material when magnetic-material sufficiently receives current-induced magnetic-field-vector, magnetic-field measuring device intermittently applies current to the conductive-body, detecting an electromotive-force generated by the coil while current is applied to the conductive-body and no current is applied to the conductive-body.

First claim

The invention claimed is:

1. A magnetic-field measuring device having: an elongate magnetic material formed of a solid or liquid having magnetic anisotropy, or a composite of said solid and liquid; an electrically conductive body disposed adjacent to said magnetic material, so as to give said magnetic material a current-induced magnetic-field vector having a component in a direction perpendicular to a longitudinal direction of said magnetic material; and a coil to detect a magnetic field generated by said magnetic material,
wherein said magnetic material is magnetized in a direction perpendicular to its longitudinal direction when an external magnetic field is not applied to said magnetic material or when only a magnetic field not having a component in its longitudinal direction is applied to said magnetic material, and is magnetized in a direction having the component in said longitudinal direction when the external magnetic field having the component in the longitudinal direction of said magnetic material is applied to said magnetic material, and
a direction of magnetization of said magnetic material is aligned with a specific direction perpendicular to the longitudinal direction of said magnetic material when the magnetic material is sufficiently given said current-induced magnetic-field vector,
said magnetic-field measuring device being
configured to intermittently apply an electric current to said electrically conductive body, and detecting an electromotive force generated by said coil while the electric current is applied to said electrically conductive body and while the electric current is not applied to the electrically conductive body.

2. The magnetic-field measuring device according to claim 1 , wherein said magnetic material is an amorphous material.

3. The magnetic-field measuring device according to claim 1 , wherein said electric current is a pulse current, a current a value of which intermittently changes in a predetermined pattern, or a current which is a composite of those two currents superimposed on each other.

4. The magnetic-field measuring device according to claim 1 , wherein said magnetic material consists of at least one amorphous wire, and said electrically conductive body consists of at least one conductor wire.

5. The magnetic-field measuring device according to claim 1 , wherein said magnetic material has a symmetrical shape with respect to a straight line or plane of symmetry which passes a midpoint in the longitudinal direction of said magnetic material, and which is perpendicular to said longitudinal direction, and said coil consists of two coils which are disposed at respective positions which are symmetrical with each other with respect to said line or plane of symmetry, whereby the magnetic-field measuring device is provided with a gradiometer.

6. The magnetic-field measuring device according to claim 1 , wherein said magnetic material includes an amorphous material having magnetic anisotropy, and said amorphous material consists of at least one cylindrical layer surrounding said electrically conductive body.

Assignees

• Univ Nagoya Nat Univ Corp
• Fujidenolo Co Ltd

Inventors

• Nakayama Shinsuke
• Miyazaki Hideki

Classifications

• G01R33/028

  Electrodynamic magnetometers · CPC title

• G01R33/02 Primary

  Measuring direction or magnitude of magnetic fields or magnetic flux (G01R33/20 takes precedence) · CPC title

• G01R33/0029 Primary

  Treating the measured signals, e.g. removing offset or noise · CPC title