Magnetometer having periodic winding structure and material property estimator

A magnetometer for measuring one or more properties of a material comprising:

• an electromagnetic structure capable of imposing a magnetic field in the material when driven by an electric signal and sensing an electromagnetic response to the magnetic field;
• an analyzer for applying the electric signal to the structure to define a spatial wavelength of the magnetic field imposed in the material;
• and P1 a property estimator coupled to the electromagnetic structure for translating sensed electromagnetic responses into estimates of one or more preselected properties of the material, wherein the sensed responses are obtained at a plurality of proximities to the material;
• wherein the electric signal has a preselected temporal excitation frequency being proximal to a transverse diffusion effect characteristic frequency for the electromagnetic structure.

A magnetometer for measuring one or more properties of a material comprising:

• an electromagnetic winding structure capable of imposing a magnetic field in the material, when driven by an electric signal and sensing an electromagnetic response to the magnetic field;
• an analyzer for applying the electric signal to the winding structure to define a spatial wavelength of the magnetic field imposed in the material, the electric signal having its temporal excitation frequency being proximal to a transverse diffusion effect characteristic frequency of the winding structure;
• and
• a property estimator providing a property estimation grid for translating sensed electromagnetic responses into estimates of one or more preselected properties of the material, wherein the property estimator comprises an algorithmic model for providing a prediction of a response for each value of each of the preselected material properties based on a set of properties characterizing the winding structure and the material, the property estimator implementing the model successively for obtaining the property estimation grid for the preselected material properties.

A magnetometer for measuring an affected zone conductivity and thickness of a processed metal comprising:

• an electromagnetic winding structure capable of imposing a magnetic field in the processed metal when driven by an electric signal and sensing an electromagnetic response, the winding structure comprising a primary winding including a conductor and a secondary winding including a conductor which is separated from the primary winding by a gap, the primary winding conductor width being substantially greater than the gap width;
• an analyzer for applying the electric signal having a preselected temporal excitation frequency to the winding structure;
• and
• a property estimator coupled to the winding structure for translating each sensed response into substantially independent conductivity and thickness estimates.

A magnetometer for measuring proximity to and conductivity of a material comprising:

• a periodic electromagnetic winding structure capable of imposing a magnetic field in the material when driven by an electric signal and sensing an electromagnetic response to the magnetic field;
• an analyzer for applying the electric signal to the winding structure to define a spatial wavelength of the magnetic field imposed in the material which is associated with the periodic winding structure, the electric signal having a preselected temporal excitation frequency;
• and
• a property estimator coupled to the winding structure for receiving sensed responses, the property estimator accessing a property estimation grid for translating sensed responses into substantially independent proximity and conductivity estimates at the single preselected temporal excitation frequency.

A magnetometer for measuring complex permeability of a material comprising:

• an electromagnetic winding structure capable of imposing a magnetic field in the material and sensing an electromagnetic response to the magnetic field, the winding structure comprising a plurality of meandering electromagnetic windings;
• an analyzer for applying an electric signal to the winding structure to define a spatial wavelength the magnetic field imposed in the material, the electric signal having a preselected temporal excitation frequency;
• and
• a property estimator coupled to the winding structure for receiving sensed responses, the property estimator providing a response prediction table for translating sensed responses into complex permeability estimates of the material, the property estimator generating the prediction table by successively implementing an algorithmic model which provides for each implementation a prediction of a response for a value of complex permeability based on a set of properties characterizing the winding structure and the material.

An apparatus for measuring one or more properties of a material comprising:

• a pair of meandering electromagnetic winding structures positioned on opposite sides of the material, each meandering winding structure being capable of posing a magnetic field in the material when driven by an electric signal and sensing an electromagnetic response to the magnetic filed;
• an analyzer for applying electric signals in plural modes of phase relationship to the meandering winding structures to define respective spatial wavelengths of the magnetic fields imposed in the material;
• and
• a property estimator coupled to the winding structures for translating electromagnetic responses from each of the pair of meandering winding structures in the plural modes of phase relationship into estimates of one or more properties of the material.

A magnetometer for measuring one or more preselected properties of a material having a curved surface comprising:

• an electromagnetic winding structure capable of being adapted to conform to the curved surface of the material, the winding structure comprising a plurality of meandering electromagnetic windings for imposing a magnetic field in a material when driven by an electric signal and sensing an electromagnetic response to the magnetic field;
• an analyzer for applying an electric signal to the winding structure to define a spatial wavelength of the magnetic field imposed in the material, the electric signal having a preselected temporal excitation frequency;
• and
• a property estimator providing a property estimation grid for translating sensed electromagnetic responses into estimates of one or more preselected properties of the material, wherein the property estimator comprises an algorithmic model for providing a prediction of a response for each value of each of the preselected material properties based on a set of properties characterizing the winding structure and the material, the property estimator implementing the model successively for obtaining the property estimation grid for the preselected material properties.

A magnetometer for measuring one or more properties of a material comprising;

• an electromagnetic winding structure comprising a primary winding including a conductor capable of imposing a magnetic field in the material when driven by an electric signal and one or more secondary windings including conductors for sensing an electromagnetic response, the secondary winding conductors being separated from the primary winding conductor by a gap and the primary winding conductor having a width which is substantially greater than the gap width;
• an analyzer for applying an electric signal to the primary winding for imposing the magnetic field in the material;
• and
• a property estimator coupled to the winding structure for translating sensed electromagnetic responses into estimates of one or more preselected properties of the material.

An apparatus for measuring one or more properties of a material comprising:

• a deposited electromagnetic winding structure comprising a meandering primary winding which imposes a magnetic field in the material when driven by an electric signal for exciting multiple spatial surface current density modes, the meandering primary winding providing a prescribed spatial wavelength associated with the winding structure, the winding structure further comprising a secondary winding which senses fields produced by a dominant spatial wavelength surface current density mode and at least one shorter wavelength mode for obtaining electromagnetic response;
• an analyzer for applying the electric signal to the winding structure;
• and
• a property estimator coupled to the winding structure for translating electromagnetic responses at the dominant and at least one shorter wavelength modes into estimates of one or more properties of the material.

A magnetometer for measuring proximity to and a second property of a material comprising:

• a periodic electromagnetic winding structure capable of imposing a magnetic field in the material when driven by an electric signal and sensing an electromagnetic response to the magnetic field;
• an analyzer for applying the electric signal to the winding structure to define a spatial wavelength of the periodic winding structure and the magnetic field imposed in the material, the electric signal having a preselected temporal excitation frequency;
• and
• a property estimator coupled to the winding structure for receiving sensed responses, the property estimator accessing a property estimation grid for translating sensed responses into substantially independent proximity and second property estimates at the single preselected temporal excitation frequency.

A magnetometer for measuring conductivity and a second property of a material comprising:

• a periodic electromagnetic winding structure capable of imposing a magnetic field in the material when driven by an electric signal and sensing an electromagnetic response to the magnetic filed;
• an analyzer for applying the electric signal to the winding structure to define a spatial wavelength of the periodic winding structure and the magnetic field imposed in the material, the electric signal having a preselected temporal excitation frequency;
• and
• a property estimator coupled to the winding structure for receiving sensed responses, the property estimator accessing a property estimation grid for translating sensed responses into substantially independent conductivity and second property estimates at the single preselected temporal excitation frequency.