US 2001/0054894 A1Published application

Apparatus and method for obtaining increased sensitivity, selectivity and dynamic range in property measurement using magnetometers

AssigneeMassachusetts Institute of Technology

InventorsNeil J. Goldfine, James R. Melcher, Janet D. Melcher

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Abstract

Apparatus and methods are disclosed which provide increased sensitivity, selectivity and dynamic range for non-contact measurement of actual physical and/or kinematic properties of conducting and magnetic materials. The apparatus and methods are based upon various methods for increasing sensitivity, selectivity and dynamic range through proper construction of a magnetometer sensor and for proper selection of operating point parameters for the application. A measurement apparatus for measuring one or more MUT properties includes an electromagnetic winding structure which, when driven by an electric signal, imposes a magnetic field in the MUT and senses an electromagnetic response. An analyzer is provided for applying the electric signal to the winding structure. A property estimator is coupled to the winding structure and translates sensed electromagnetic responses into estimates of one or more preselected properties of the material.

Claims3

Dependent claims

A method for generating property estimates of one or more preselected properties of a material comprising:

providing an electromagnetic structure capable of imposing a magnetic field in the material when driven by an electric signal and sensing an electromagnetic response, an analyzer for applying an electric signal to the electromagnetic structure and a property estimator for translating sensed responses into estimates for one or more preselected properties to the material;
defining a dynamic range for the preselected properties of the material;
selecting an electromagnetic winding geometry and configuration for the electromagnetic structure;
generating property estimation grids for the preselected material properties and analyzing the grids and curves to define a measurement strategy;
optimizing operating point properties and winding geometry and configuration;
sensing electromagnetic responses at each operating point;
and
converting electromagnetic responses into estimates of the preselected material properties.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/758,768Filed 11 Jan 2001
Priority: 21 May 1999
Published: 27 Dec 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G01B 7/105
Using magnetic means, e.g. by measuring change of reluctance: for measuring thickness of coating
G01N 27/72
Investigating or analysing materials by the use of electric, electrochemical, or magnetic means: by investigating magnetic variables
G01N 27/9046
Using eddy currents: by analysing electrical signals
G01R 33/1223
Measuring magnetic properties of articles or specimens of solids or fluids: measuring permeability, i.e. permeameters

Family

Application09/316,249Division · filed 21 May 1999
Application09/758,768Division · filed 11 Jan 2001
US 6,252,398 B1Related patent
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US 2001/0054894 A1This patent

From the US filing history. Foreign family members aren’t listed.