Other

University of California

4d Imaging, Inc.

Singer Imaging, Inc.

Jerome R Singer

Joel M Libove

Glen Stevick

David Rondinone

Mitsuaki A Arakawa

Lawrence E Crooks

John C Hoenninger, Iii

John L Couch

Allan L Sagle

Philip D Kohn

Francisco A Grunbaum

Matthew D Rocklin

Jorge P Zubelli

Steven Chacko

Harold L Naparst

John Zalabak

Geoffrey Latham

A leak alarm system for a petroleum pipeline includes one or more detectors installed in the ground adjacent to a pipeline, each detector having a tubular enclosure with a diode light source and photosensor located at the opposed end of the tube. The tubular enclosure is fabricated of a microporous material that has microfiltration properties: it is hydrophobic, so that soil water will not enter the enclosure, but also oleophilic to enable petroleum and related substances migrate through the material of the tubular enclosure and accumulate therein. The petroleum-like materials scatter the beam and diminish the sensor signal, causing a leak alarm signal to be generated.

Method and apparatus for detecting and monitoring oil spills and leaks

A method for identifying, measuring, and monitoring metal loss through corrosion ferromagnetic piping includes drive coils secured to the pipe and driven to emit a magnetic field which is transmitted through the object by magnetic domains in the object. Response coils detect the magnetic domains and generate a response signal. Response coils may be saddle or loop coils, or printed coils on flexible substrates that are applied to conform to the pipe peripheral surface. The system operates reiteratively over an extended period of time to detect loss of magnetic domains which is an important indicator of corrosion and deterioration of the object.

Method and apparatus for magnetic response imaging

An apparatus and method for identifying, measuring, and monitoring metal loss through corrosion or other deleterious factors in ferromagnetic piping and ferromagnetic objects. Drive coils secured to the object are driven to emit a magnetic field which is transmitted through the object by magnetic domains in the object. Response coils detect the magnetic domains and generate a response signal. The drive and response signals can penetrate insulating materials and non-ferromagnetic metallic coverings of the piping and vessels. The system operates reiteratively over an extended period of time, e.g., months or years, to detect loss of magnetic domains which is an important indicator of corrosion and deterioration of the object.

A method for creating a 3D map of the surface contours of an object includes projecting a variety of patterns onto the object, and imaging the patterns as they fall on the object to encode the topographic features of the object. In one embodiment a three dimensional image is taken in a single flash to avoid blurring due to motion of the object. Thereafter a secondary pattern is projected to detect changes in the initial image. The images are processed in a computer program in a manner such that a complete 3D map of the surface of the object is obtained in digital form. Reiteration of the method can detect motional variation such as a breathing human, flexure of a complex mechanical structure, or a stress-strain testing of an airplane, vehicle, beam, bridge, or other structure.

Method and apparatus for dynamic space-time imaging system

A method for creating a 3D map of the surface contours of an object includes projecting a variety of patterns onto the object, and imaging the patterns as they fall on the object to encode the topographic features of the object. The images are processed in a computer program in a manner such that a complete 3D map of the surface of the object is obtained in digital form. Reiteration of the method can detect motional variation such as a breathing human, flexure of a complex mechanical structure, or a stress-strain testing of an airplane, vehicle, beam, bridge, or other structure.

An apparatus for performing non-contacting measurements of the voltage of a conductor includes a conducting membrane coupled to a transducer. The membrane is driven with an A.C. reference voltage, creating alternating attractive and repulsive electrostatic forces caused by the difference in potential between the membrane and the conductor. The transducer generates a signal having the same frequencies as the forces on the membrane, and the amplitudes of the A.C. components are proportional to the unknown voltage on the conductor. By dividing the amplitude of the A.C. components, an accurate determination of the unknown voltage is calculated A plurality of membranes and transducers may be arrayed to provide an image of multiple voltage readings. In addition, it is also possible to measure A.C. and D.C. voltage on the center conductor of an insulated wire without the need to pierce the insulation.

Method and apparatus for measuring D.C. and A.C. voltages using non-contacting sensors

A device for non-contact, non-invasive measurement of current or power in a wire, cable or conductor includes a small coil having multiple turns and no ferromagnetic core. The coil may be secured to a wand or housing adapted to be used to place the coil in close proximity to the wire, cable or conductor, whereby a voltage is induced in the coil. An amplifier may be utilized to increase sensitivity. A readout indicates the magnitude of the induced voltage, and a scaling device renders the readout display indicative of the current or power in the wire, cable, or conductor. To measure direct current flow, the coil may be vibrated or rotated adjacent to the conductor to cause the magnetic field to induce a voltage in the coil. The readout may comprise a digital display, a series of light emitting devices, or a flashing light emitting device having a flash rate proportional to the magnitude of the voltage. The device may be constructed in a wand or pen-like fashion, with the coil incorporated into the wand. The device may be combined with a voltage sensor.

Apparatus for fast measurements of current and power with scaleable

A device for non-contact, non-invasive measurement of current or power in a wire, cable or conductor includes a small coil having multiple turns with a thin ferromagnetic strip. The coil may be secured to a wand or housing adapted to be used to place the coil in close proximity to the wire, cable or conductor, whereby a voltage is induced in the coil. An amplifier and or an analog or digital signal processor is utilized to increase sensitivity. A readout indicates the magnitude of the induced voltage, and a scaling device renders the readout display indicative of the current or power in the wire, cable, or conductor. The readout may comprise a digital display, a series of light emitting devices, an oscilloscope, a digital computer display system, or a flashing light emitting device having a flash rate proportional to the magnitude of the voltage. The device may be constructed in a wand or pen-like fashion, with the coil and strip incorporated into the wand. The device may be combined with a voltage sensor to read out relative voltages.

Method and apparatus for rapid determinations of voltage and current in

An apparatus for performing non-contacting measurements of the voltage, current and power levels of conductive elements such as wires, cables and the like includes an arrangement of capacitive sensors for generating a first current in response to variation in voltage of a conductive element. Each sensor is positioned in an electric field of the conductive element, and is thereby coupled to the conductive element through a coupling capacitance. A reference source drives the capacitive sensor arrangement at a reference frequency so as to induce the flow of a reference current therethrough. A measurement network is disposed to calculate the coupling capacitance based on a measurement of the reference current, and to then determine the voltage in the conductive element based on the first current and the coupling capacitance. Measurements of a composite current through single or multiple-element conductors may be effected using a similar procedure, wherein the composite current induces a measurement current to flow within a set of coils positioned in a predetermined manner proximate the conductor. In both current and voltage measurements a balancing procedure may be employed, in which a measurement signal is balanced by a feedback signal so as to improve accuracy and reduce the effects of stray coupling.

Apparatus for measuring voltages and currents using non-contacting

An imaging system generates images of the interior of an object using radiation which is attenuated and scattered by the interior of the object. The object is radiated at a number of points near the exterior of the object, and the radiation emerging from the object is measured at an array of exit points near the exterior of the object. The interior of the object is modelled as an array of volume elements called voxels. Each voxel is modelled as having scattering and attenuation properties, represented by numerical coefficients. The system computes the intensity of radiation that would emerge from the object at the exit points if the interior of the object were characterized by a currently assigned set of values for the scattering and attenuation coefficients. Then, the differences between the measured intensities and the computer intensities are used to compute an error function relates to the magnitude of the errors in the reconstruction. This error function is then minimized using a gradient descent methodology, i.e., the value of the coefficients are modified so as to reduce the value of the error function. The coefficients are repeatedly updated in this manner until the error function falls below a specified threshold value. The final values of the scattering and attenuation coefficients from this process are mapped so as to generate a series of images of the interior of the object depicting the attenuation and scattering characteristcs of the object's interior.

Imaging system and method using scattered and diffused radiation

An imaging NMR scanner generates multi-dimensional NMR spin echo responses from selected sub-volumes of an object. 90.degree. and 180.degree. r.f. nutation pulses are used together with a variable amplitude gradient between these nutation pulses to phase encode a second dimension in the spin echo response which is already phase-encoded in a first dimension by use of a magnetic gradient during signal readout. Two-dimensional Fourier transforms or multiple angle projection reconstruction processes are then used to generate an array of pixel value data signals representing a visual image of the point-by-point spatial distribution of nutated nuclei within the object. Image artifacts potentially caused by relatively moving elements of the object are avoided by selecting the spin echo generating sub-volumes to avoid the moving elements. High resolution images of sub-volumes of interest can be obtained by selection of a sub-volume of interest in conjunction with these reconstruction techniques. Solutions for possible aliasing artifacts are also presented as are three-dimensional reconstruction techniques using NMR spin echo responses from such selected sub-volumes.

Method and apparatus for rapid NMR imaging using multi-dimensional

Quantitative volumetric flow rates within highly defined regions are determined by a novel technique in which nuclear magnetic resonance is used to determine the fill time for the region of interest. The technique involves the combination of a depolarization pulse (or series of pulses) and a signal generating pulse (or series of pulses), both applied to a specific tomographic region and separated from each other by a time interval of varying length. The pulses are designed to cancel each other out in terms of signal generation, and the signal detected is therefore attributable to matter flowing into the region during the interval between the pulses. The fill time is determined from a plot of signal intensity vs. interval length. The process is readily combined with known NMR imaging techniques to provide a two-dimensional array of flow data.

Method for flow measurement using nuclear magnetic resonance

Flow rates across a flat panel are determined in a non-intrusive manner by a novel technique involving the use of nuclear magnetic resonance (NMR). NMR signals requiring two or more time-spaced nuclear spin excitations are generated in a selective manner, whereby at least two of the excitations are confined to preselected tomographic regions which are non-coextensive in the direction of flow, i.e., at least a portion of each region lies outside the other. The relative positions of the volumes ranges from a partial overlap to a complete separation with a gap in between. Flow detection is derived from signals reflecting movement from one such region to the other during the interval of time between the excitations. Quantitative or qualitative flow data may be obtained, including full range velocity distributions for systems where a range of velocities is present. The process is readily combined with known NMR imaging techniques to provide a two-dimensional array of flow data.

Growing community of inventors

Berkeley, CA, United States of America

Jerome R Singer