Abstract: Certain disclosed methods include: transmitting an excitation signal into the MUT and transmitting a reference signal to a set of magnitude and phase (M/P) detectors; receiving the response signal; separately comparing a magnitude and phase for each of the excitation signal and the reference signal with corresponding detection ranges for a first one of the M/P detectors; separately comparing a magnitude and phase for each of the response signal and the reference signal with corresponding detection ranges for a second one of the M/P detectors; iteratively adjusting the excitation signal until the response signal has both a magnitude and a phase within the corresponding detection ranges for the second M/P detector; and iteratively adjusting the reference signal until the reference signal has both a magnitude and a phase within the corresponding detection ranges for the first and the second M/P detectors.

Abstract: Various aspects of the disclosure relate to evaluating the electromagnetic impedance characteristics of a material under test (MUT) over a range of frequencies. In particular aspects, a system includes: an electrically non-conducting container sized to hold the MUT, the electrically non-conducting container having a first opening at a first end thereof and a second opening at a second, opposite end thereof; a transmitting electrode assembly at the first end of the electrically non-conducting container, the transmitting electrode assembly having a transmitting electrode with a transmitting surface; and a receiving electrode assembly at the second end of the electrically non-conducting container, the receiving electrode assembly having a receiving electrode with a receiving surface, wherein the receiving electrode is approximately parallel with the transmitting electrode, and wherein the transmitting surface of the transmitting electrode is larger than the receiving surface of the receiving electrode.

Abstract: Various implementations include systems and approaches for measuring an electromagnetic impedance characteristic of a fluid under test (FUT) in a fluid channel. In some cases, a system includes: a transmitting electrode assembly including: a transmitting electrode having a transmitting surface; and a transmitting electrode backer ground plate at least partially surrounding the transmitting electrode; a receiving electrode assembly including: a receiving electrode having a receiving surface; and a receiving electrode backer ground plate at least partially surrounding the receiving electrode, where the transmitting electrode and the receiving electrode are located in a set of walls defining the fluid channel, the transmitting surface and the receiving surface each conform to a shape of the set of walls defining the fluid channel, where the fluid channel permits transverse flow of the FUT relative to both the transmitting electrode and the receiving electrode.

Abstract: According to various implementations, an apparatus for electromagnetic impedance spectrographic characterization of a material under test (MUT) includes: a planar array of at least two electrodes configured to be placed in electromagnetic communication with the MUT, wherein during operation of the planar array, at least one of the electrodes comprises a transmitting electrode for transmitting an electromagnetic signal over a range of frequencies through the MUT to at least one receiving electrode in the planar array; and a backer ground plate at least partially surrounding the at least two electrodes, the backer ground plate being electrically grounded and insulated from the at least two electrodes, wherein the backer ground plate extends from a plane formed by the at least two electrodes and separates the at least two electrodes to create an electrically isolated volume proximate to the at least two electrodes.

Abstract: Certain disclosed methods include: transmitting an excitation signal into the MUT and transmitting a reference signal to a set of magnitude and phase (M/P) detectors; receiving the response signal; separately comparing a magnitude and phase for each of the excitation signal and the reference signal with corresponding detection ranges for a first one of the M/P detectors; separately comparing a magnitude and phase for each of the response signal and the reference signal with corresponding detection ranges for a second one of the M/P detectors; iteratively adjusting the excitation signal until the response signal has both a magnitude and a phase within the corresponding detection ranges for the second M/P detector; and iteratively adjusting the reference signal until the reference signal has both a magnitude and a phase within the corresponding detection ranges for the first and the second M/P detectors.

Abstract: Various aspects of the disclosure relate to evaluating the electromagnetic impedance characteristics of a material under test (MUT) over a range of frequencies. In particular aspects, a system includes: an electrically non-conducting container sized to hold the MUT, the electrically non-conducting container having a first opening at a first end thereof and a second opening at a second, opposite end thereof; a transmitting electrode assembly at the first end of the electrically non-conducting container, the transmitting electrode assembly having a transmitting electrode with a transmitting surface; and a receiving electrode assembly at the second end of the electrically non-conducting container, the receiving electrode assembly having a receiving electrode with a receiving surface, wherein the receiving electrode is approximately parallel with the transmitting electrode, and wherein the transmitting surface of the transmitting electrode is larger than the receiving surface of the receiving electrode.

Abstract: According to various implementations, an apparatus for electromagnetic impedance spectra graphic characterization of a material under test (MUT) includes: a planar array of at least two electrodes configured to be placed in electromagnetic communication with the MUT, wherein during operation of the planar array, at least one of the electrodes comprises a transmitting electrode for transmitting an electromagnetic signal over a range of frequencies through the MUT to at least one receiving electrode in the planar array; and a backer ground plate at least partially surrounding the at least two electrodes, the backer ground plate being electrically grounded and insulated from the at least two electrodes, wherein the backer ground plate extends from a plane formed by the at least two electrodes and separates the at least two electrodes to create an electrically isolated volume proximate to the at least two electrodes.

Abstract: Various aspects of the disclosure relate to evaluating the electromagnetic impedance characteristics of a material under test (MUT) over a range of frequencies. In particular aspects, a system includes: an electrically non-conducting container sized to hold the MUT, the electrically non-conducting container having a first opening at a first end thereof and a second opening at a second, opposite end thereof; a transmitting electrode assembly at the first end of the electrically non-conducting container, the transmitting electrode assembly having a transmitting electrode with a transmitting surface; and a receiving electrode assembly at the second end of the electrically non-conducting container, the receiving electrode assembly having a receiving electrode with a receiving surface, wherein the receiving electrode is approximately parallel with the transmitting electrode, and wherein the transmitting surface of the transmitting electrode is larger than the receiving surface of the receiving electrode.

Abstract: Systems and methods for measuring and monitoring physical properties of a material under test (MUT) from a vehicle, e.g., using complex electromagnetic impedance. Various embodiments include a method including: obtaining displacement data about a position of a sensor array relative to a material under test (MUT); comparing the displacement data with reference displacement data to determine whether the sensor array is at a reference distance relative to the MUT; in response to determining that the sensor array is located at the reference distance, instructing the sensor array to transmit a set of electromagnetic impedance signals into the MUT; obtaining a return electromagnetic impedance signal from the MUT; and calculating at least one physical property of the MUT based upon the transmitted set of electromagnetic impedance signals, the return electromagnetic impedance signals, and the displacement data.

Abstract: Approaches include selecting a desired location for the measurement of electromagnetic spectroscopic impedance data for correlation with a physical property of a material under test (MUT) with electromagnetic impedance tomography. The MUT is first characterized tomographically with a series of four-terminal electrode patterns at a single current frequency. Measured and computed values of electromagnetic impedance for the voxels and sub-voxels of the MUT are determined. The sub-voxel with a targeted value of impedance is selected and matched with the specific four-terminal electrode pattern related to that sub-voxel. The spectrographic electromagnetic impedance measurements are made across a range of frequencies for the selected sub-voxel, using all of the four-terminal electrode patterns required to compute the tomographic impedance value of the selected sub-voxel. The computed spectrographic electromagnetic impedance value for the selected sub-voxel is then correlated to a physical property of the MUT.

Abstract: Embodiments include a system and circuit for measuring characteristics of a material under test (MUT). In some cases, the system includes a circuit having level detectors to measure the change in strength between a reference signal and a return signal passed through the MUT. The system can include a computing device to evaluate the measured signals and adjust those signals within range of the level detectors and other circuit components. Circuits can include a time-of-flight digital convertor for determining the phase shift between the reference and return signals that pass through the MUT. The measured difference in signal strength and phase can be used to compute the complex impedance or dielectric properties of the MUT. This impedance or dielectric property can be correlated with a physical property of the MUT. The system may be operated at a single frequency, or over a range of frequencies.

Abstract: A method of extracting complex impedance from selected volumes of the material under test (MUT) combined with various embodiments of electrode sensor arrays. Configurations of linear and planar electrode arrays provide measured data of complex impedance of selected volumes, or voxels, of the MUT, which then can be used to extract the impedance of selected sub-volumes or sub-voxels of the MUT through application of circuit theory. The complex impedance characteristics of the sub-voxels may be used to identify variations in the properties of the various sub-voxels of the MUT, or be correlated to physical properties of the MUT using electromagnetic impedance tomography and/or spectroscopy.

Abstract: Methods of extracting complex impedance from selected subsurface volumes of a material under test (MUT) using various embodiments of electrode sensor pairs are provided. The electrode pairs can penetrate into a subsurface of the MUT, and operate below the surface of the MUT. Configurations of electrode pair sensors provide measured data of complex impedance of selected subsurface volumes of the MUT using electromagnetic spectrographic signals over a frequency range. The complex impedance characteristics of the subsurface volumes may be used to identify variations in the properties of the MUT, or be correlated to physical properties of the MUT.

Abstract: Various embodiments include planar sensor arrays for use in determining characteristics of a material under test (MUT). The planar sensor arrays can include a set of electrodes positioned to enhance a depth and clarity of detection into the material under test. Some embodiments include an electromagnetic sensor array having: a first set of two rectilinear electrodes, positioned opposed to one another across a space; and a second set of two rectilinear electrodes, positioned opposed to one another across the space, the second set being off-set from the first set, wherein the first set and the second set are configured to detect an electromagnetic impedance of the MUT.

Abstract: Apparatuses, systems, methods, and computer program products are presented for electronically emulating the impedance characteristics of materials, e.g., for standardizing and calibrating electromagnetic measuring devices for the measurement of physical properties of materials. The electronic impedance emulation apparatus according to some embodiments includes an electronic material emulation circuit in communication with the electromagnetic measuring device. The electronic material emulation circuit and the electromagnetic measuring device are controlled by a at least one computing device, which can control the frequency of signal(s) generated by the electromagnetic measuring device. The at least one computing device can instruct the electronic emulator to produce signals having complex impedance characteristics of the material under test at the test frequency. The emulation data can be stored and used for the calibration and/or standardization of the electromagnetic measuring device.

Abstract: A method of extracting complex impedance from selected volumes of the material under test (MUT) combined with various embodiments of electrode sensor arrays. Configurations of linear and planar electrode arrays provide measured data of complex impedance of selected volumes, or voxels, of the MUT, which then can be used to extract the impedance of selected sub-volumes or sub-voxels of the MUT through application of circuit theory. The complex impedance characteristics of the sub-voxels may be used to identify variations in the properties of the various sub-voxels of the MUT, or be correlated to physical properties of the MUT using electromagnetic impedance tomography and/or spectroscopy.

Abstract: Various embodiments include solutions for in-process material characterization. Various particular embodiments include a computer-implemented method including: providing instructions for transmitting oscillating electromagnetic field signals to a material under test (MUT); obtaining a return signal associated with the transmitted oscillating electromagnetic field signals; comparing the return signal with the oscillating electromagnetic field signals to determine a difference in an aspect of the return signal and the aspect of the oscillating electromagnetic field signals; comparing the difference in the aspect to a predetermined threshold; and determining a characteristic of the MUT based upon the compared difference.

Abstract: Methods include: providing instructions to a signal generator to transmit a first set of tomographic signals to a surface and a subsurface beneath the surface; obtaining a first return signal about the surface and the subsurface beneath the surface, the first return signal associated with the first set of tomographic signals; comparing the first return signal with the first set of tomographic signals to determine whether an object is present within the subsurface; providing instructions to the signal generator to transmit a set of spectrographic signals to the surface and subsurface in response to determining the object is present within the subsurface; obtaining a second return signal about the surface and subsurface beneath the surface, the second return signal associated with the set of spectrographic signals; and comparing the second return signal with the set of spectrographic signals to determine a characteristic of the object within the subsurface.

Abstract: Various embodiments of the invention relate generally to the measurement of the impedance of materials, electronic devices, or components over a range of frequencies, with a system for self-adjusting an input transmit signal and/or a reference signal to produce a measured signal within a desired range of the electronic measuring components over the frequency range based upon the value of the measured signal.

Abstract: Apparatuses, systems, methods, and computer program products are presented for electronically emulating the impedance characteristics of materials, e.g., for standardizing and calibrating electromagnetic measuring devices for the measurement of physical properties of materials. The electronic impedance emulation apparatus according to some embodiments includes an electronic material emulation circuit in communication with the electromagnetic measuring device. The electronic material emulation circuit and the electromagnetic measuring device are controlled by a at least one computing device, which can control the frequency of signal(s) generated by the electromagnetic measuring device. The at least one computing device can instruct the electronic emulator to produce signals having complex impedance characteristics of the material under test at the test frequency. The emulation data can be stored and used for the calibration and/or standardization of the electromagnetic measuring device.