A measuring apparatus for electromagnetic property of material includes a chamber and a specified shielding piece. The chamber has a cavity inside and the chamber has an electromagnetic wave access terminal to connect to the cavity, used to receive an input electromagnetic wave and output a reflective electromagnetic wave. The specified shielding piece is disposed inside the cavity with respect to the electromagnetic wave access terminal, used to produce a region in side the cavity. The region is dominated by magnetic field and is used to adapt an object to be measured.

Acoustic imaging tools and methods use refracted wave amplitudes to generate borehole images, thereby providing a method and tool that is highly sensitive to borehole discontinuities.

An apparatus and a method for the non-destructive determination of the content of the magnetizable and/or non-magnetizable portion of a sample, in which the sample is provided in an air gap of a magnetically conductive yoke, an alternating magnetic field is generated by means of an alternating magnetic field strength of an excitation coil in the yoke, and first measurement data relating to the sample are collected using at least one measuring device which is inductively coupled to the yoke, and the magnetizable and/or non-magnetizable content portion in the sample is determined by comparing the first measurement data to second measurement data relating to a reference sample that has a known magnetizable and/or non-magnetizable content portion, wherein the same alternating magnetic field strength or the same alternating magnetic field is applied to both the reference sample and the sample and the difference between the two collected sets of measurement data is included as a measure in the determination of the content for the magnetizable and/or non-magnetizable content portion of the sample.

Each of the oscillation frequency of a first oscillation circuit performing oscillation in a state of including a coil and a capacitor and the oscillation frequency of a second oscillation circuit performing oscillation in a state of including a coil and a capacitor different from the coil and the capacitor of the first oscillation circuit is measured. Then, the difference of the measured oscillation frequencies is calculated and then the calculated difference is converted into a magnetic permeability or a dielectric permittivity. One sensor selectively detects a change in the magnetic permeability or a change in the dielectric permittivity of a subject material.

A differential transformer-based permeability sensor includes a substrate including an insulation layer and a wiring layer stacked on each other, a first drive coil, a first induction coil, a second drive coil, a second induction coil, and a adjuster coil, all flatly formed on the wiring layer, a closed circuit including the adjuster coil and a current regulation element connected in parallel to ends of the adjuster coil, and an oscillation circuit. A circuit constituent is formed in which an oscillation signal of the oscillation circuit is provided to each of the drive coils, so that an induction current flows through the first induction coil, the second induction coil, and the adjuster coil, and a difference between the induction current of the first induction coil and that of the second induction coil is outputted. The induction current of the adjuster coil is adjusted according to resistance of a variable resistor.

A method includes receiving, from a plurality of magnetic field receivers including magnetic sensors, data characterizing samples obtained by the plurality of magnetic field receivers, the samples of a combination of a first magnetic field and a second magnetic field resulting from interaction of the first magnetic field and an object; determining, using the received data, a polarizability index of the object, the polarizability index characterizing a magnetic polarizability property of the object; classifying, using the determined polarizability index, the object as threat or non-threat; and providing the classification. Related apparatus, systems, techniques, and articles are also described.

A sensor arrangement for determining a process variable of a medium in a containment comprises a sensor apparatus, a magnetic field apparatus, and a detection apparatus. The magnetic field apparat produces a magnetic field that penetrates the sensor apparatus, the detection apparatus and partially the medium. The sensor apparatus is embodied such that a magnetic property of a component of the sensor apparatus depends on the process variable, and the magnetic field of the magnetic field apparatus is influenceable by the sensor apparatus as a function of process variable. The detection apparatus is embodied to register a variable related with the magnetic field, especially the magnetic flux density, the magnetic susceptibility or the magnetic permeability, and, based on that variable, to determine the process variable. The sensor apparatus is arranged within an internal volume of the containment and the detection apparatus is arranged outside of the containment.

The present invention is a ferrobody magnetic permeability mapping system including a ferrobody material, a first magnetic generator, a second magnetic generator in electrical communication with the first magnetic generator and configured to present an alternating magnetic field, a control circuit configured for alternating operation of the first and second magnetic generators; the magnetic permeability sensor being configured for measuring the magnetic permeability of the ferrobody material in response to the alternating magnetic field; the magnetic permeability sensor including a matrix comprising at least one row select circuitry and at least one column select circuitry wherein the magnetic permeability of the ferrobody material is obtained by the row select circuitry and the column select circuitry where magnetic permeability values of the ferrobody material is obtained at multiple locations within the alternating magnetic field.

Provided is a technology for detecting a change in an inspection target containing moisture. A sensor circuit (1) for inspecting property of an inspection target includes an oscillator (20) having a resonance frequency of 30 to 200 GHz, and a detection circuit (3) that estimates an oscillation frequency of the oscillator.

A multi-layer wireless sensor construct is provided. The construct includes a first dielectric layer adapted to be attached to a portion of a first surface of an electrically-conductive material. A layer of mu metal is provided on the first dielectric layer. A second dielectric layer is provided on the layer of mu metal. An electrical conductor is provided on the second dielectric layer wherein the second dielectric layer separates the electrical conductor from the layer of mu metal. The electrical conductor has first and second ends and is shaped to form an unconnected open-circuit that, in the presence of a time-varying magnetic field, resonates to generate a harmonic magnetic field response having a frequency, amplitude and bandwidth.