Innerspec Technologies, Inc

Borja Lopez Jauregui

Philip Haywood Cox

Nathaniel Quinn Huggins

This disclosure relates to the inspection of train wheels while mounted on a train that is moving on a railroad track. A magnetostrictive EMAT transducer is built using an RF Coil, a static biasing magnetic field, and a strip of highly magnetostrictive material. This magnetostrictive EMAT transducer is subsequently attached to a rail on the track so the wheel tread of the moving train can contact and apply downward pressure on the magnetostrictive EMAT transducer. A mechanism under the transducer provides enough counterforce to pressure-couple the transducer with the tread of the wheel. Once the transducer is ultrasonically coupled with the wheel, an ultrasonic instrument sends a pulse to the transducer generating a Shear Horizontal wave that travels circumferentially following the tread body. The Shear Horizontal wave generated with this magnetostrictive strip EMAT transducer penetrates deep into the wheel tread and permits detection of both surface and internal defects.

Magnetostrictive EMAT for in-motion inspection of railroad wheels

An automatic impedance matching system that reads the input impedance of an electromagnetic acoustic transducer (EMAT) electrical circuit and automatically select appropriate input impedance matching by combining components from a built-in selection of a matching circuitry. A Vector Network Analyzer or similar impedance measuring circuit is connected to the EMAT electrical circuit to measure the input impedance of the EMAT electrical circuit comprising an RF coil, coil cable, and conductive material to be inspected at a given material lift-off, and to relay measurement information to the system processor. The processor uses this information to adjust the overall input impedance of the EMAT electrical circuitry by selecting appropriate components such as capacitors and transformer taps of the built-in selection of the matching circuitry connected between the system pulser/receiver and the coil cable. As such, the overall impedance of the EMAT electrical circuit can be adjusted to best match a desired impedance that would optimize performance of the EMAT which is based on a measured acoustic signal transmission coefficient or a measured acoustic signal reflection coefficient of the EMAT. The system can work in either pulse-echo (same transmitter and receiver) or pitch-catch (different transmitter and receiver).

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Lynchburg, VA, United States of America

Borja Lopez Jauregui