Southwest Research Institute

Karta Technologies, Inc.

Charles E Duffer

Glenn M Light

Sergey A Vinogradov

Adam C Cobb

Jonathan Bartlett

Pavan Kumar Shukla

Sang Young Kim

Jorge J Alcoz

Alan R Puchot

A ferromagnetic strip sensor for use in magnetostrictive testing of various structures. In its simplest form, the sensor has a ferromagnetic strip with an electrical coil winding. A permanent magnet is positioned atop the strip, aligned with but offset from, a center axis of the strip. The sensor is operable such that a time varying current in the coil results in a unidirectional guided wave. This guided wave travels within the structure, and is reflected from anomalies in the structure.

Non destructive magnetostrictive testing with unidirectional guided waves generated by ferromagnetic strip sensor

Various embodiments of magnetostrictive transducers (MsTs) for detecting defects in a tubular structure comprise one or more AC coils and one or more magnets. The transducer has a pair of coils (or two coil elements), which are spaced 180 degrees apart relative to the circumference of the tubular structure. Each MsT is selectively operable or configurable so that it may generate either torsional or flexural guided waves.

Paired magnetostrictive transducers for non destructive testing of tubular structures with selective torsional or flexural wave modes

A probe for use in magnetostrictive testing of tubular structures. The probe has a handle and an outer tube, the latter having an expandable probe head for insertion into the tubular structure. A pair of magnetostrictive sensors is mounted in or on the probe head. A flexible bladder is located inside the outer tube in the area of the probe head, and communicates with a pressurizing cartridge in the probe handle via a bladder tube. The bladder is operable to expand, causing the probe head to expand, which moves the sensors toward the inner wall of the tubular structure. The probe is also equipped with a couplant injector that delivers coupling fluid to any gaps between the inner surface of the tubular structure and the outer surface of the probe.

Magnetostrictive probe with mechanical and fluid coupling for guided wave testing of tubular structures

A flexible printed circuit board (PCB) magnetostrictive (MS) sensor comprising a first direct current (DC) bias PCB layer comprising a first plurality of conductive traces, a first alternating current (AC) PCB layer disposed on the first DC bias PCB layer, the first AC PCB layer comprising a first AC coil, a pocket PCB layer disposed on the first AC PCB layer, the pocket PCB layer to receive a strip of MS material, a second AC PCB layer disposed on the pocket PCB layer, the second AC PCB layer comprising a second AC coil, and a second DC bias PCB layer disposed on the second AC PCB layer, the second DC bias PCB layer comprising a second plurality of conductive traces. The traces from the first plurality of conductive traces are electrically coupled to traces from the second plurality of conductive traces.

Flexible magnetostrictive sensor

An ultrasonic probe that uses the magnetostrictive effect to generate and detect a surface-coupled guided wave for the purpose of inspecting a thick-walled structure for surface defects. A transmitter sensor and a receiver sensor are especially designed to generate and detect short wavelengths that will couple to only one surface of the plate.

Magnetostrictive probes for surface wave testing of thick walled structures

A system for controlling process temperatures for semi-conductor wafers comprises a heater to heat the wafer, an element to generate a plurality of ultrasonic vibrations in the wafer, a Sagnac interferometer adapted to sense the ultrasonic vibrations and generate a wafer temperature signal responsive thereto, a system to calculate the wafer temperature on the basis of the generated wafer temperature signal, and a control element the wafer heater on the basis of the calculated wafer temperature. A method for controlling process temperatures for semi-conductor wafers comprises the steps of heating the wafer, generating a plurality of ultrasonic vibrations in the wafer, sensing the ultrasonic vibrations with a Sagnac interferometer, generating the wafer temperature signal in response to sensing the ultrasonic vibrations with the Sagnac interferometer, calculating the wafer temperature on the basis of the generated wafer temperature signal, and controlling the heat applied to the wafer on the basis of the calculated wafer temperature.

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San Antonio, TX, United States of America

Charles E Duffer