Abstract: A guided wave electromagnetic acoustic transducer for detecting defects in moving metallic products such as rods, tubes and the like and which has coils energized by pulse of a few cycles of a high frequency alternating voltage which produces an alternating field in the product, the coils being alternately wound and connected in series and measuring dynamic acoustic stress that is a function of the radial distance from the center of the product being tested and produces a reading that is different than that showing a surface defect in the product.

Abstract: This invention relates to a Electromagnetic Acoustic Transducer which has the ability to detect flaws in assorted metallic objects, such as pipes, rods, bars and the like, including those objects which are already installed and cannot be removed without a major undertaking. The Transducer also has an embodiment which includes hinged arms for surrounding the circular objects that have already been installed such as piping. The system employs Lamb waves to move along the surface of metallic objects to affect a bounced return to thereby allow detection of flaws on the surface or in the interior of said objects.

Abstract: A EMAT inspection system is utiliized on sheet metal prior to it being formed or rolled to identify surface defects and sub-surface defects such as pencil pipe inclusions by using ultrasonic Lamb waves with the results being displayed on a remote screen of a display and control system which also records the inspection results and controls the EMAT system.

Abstract: An automated sensor transport system for non-destructive inspection of a weld through the use of ultrasonic waves produced by an electromagnetic acoustic transducer (EMAT). The system includes: a computer control unit; a transport apparatus having a first EMAT for producing an ultrasonic SH shear wave and a second EMAT for receiving an ultrasonic SH shear wave reflected from a weld and a calibration means. The computer control unit, which is in electrical communication with a welding apparatus, the transport apparatus and a data acquisition unit, coordinates the weld test with completion of the weld. An edge detection sensor, which is affixed to the transport apparatus is used to automatically position the transport apparatus for a weld scan and to signal completion of the scan. The system includes an electrostatic shield to protect the second EMAT from electromagnetic and radio frequency interference.

Abstract: An EMAT inspection system is utilized on a mill roll to identify surface and sub-surface defects such as firecracks in steel mill rolls with the results being displayed on a remote screen of a display and control system which also records the inspection results and controls the EMAT system.

Abstract: An automated method for non-destructive inspection and evaluation of a weld through the use of ultrasonic waves produced by an electromagnetic acoustic transducer (EMAT). The method includes automatic positioning of a transport apparatus containing EMAT transmitter and receiver coils in proximity of a just-completed weld; scanning the weld; receiving an electrical signal produced in the EMAT receiver coil by a reflected ultrasonic SH shear wave; recording and monitoring the electrical signal; analyzing tie electrical signal relative to predetermined control limits; signaling the presence of a defect in the weld; and communicating electronically with a welding apparatus to reperform and/or alter the way in which subsequent welds are made so as to avoid repetition of the defect. The method also includes automatic receiving, recording, and monitoring of welding apparatus and welding process data, as well as automatic adjustment of corresponding welding apparatus and welding process parameters.

Abstract: An automated system for non-destructive inspection of a weld through the use of ultrasonic waves produced by an electromagnetic acoustic transducer (EMAT). The system includes: a computer control unit; a transport apparatus having a first EMAT for producing an ultrasonic SH shear wave and a second EMAT for receiving an ultrasonic SH shear wave reflected from a weld; a data acquisition unit and a calibration means. The computer control unit, which is in electrical communication with a welding apparatus, the transport apparatus and the data acquisition unit, coordinates the weld test with completion of the weld. An edge detection sensor, which is affixed to the transport apparatus is used to automatically position the transport apparatus for a weld scan and to signal completion of the scan. The system includes an electrostatic shield to protect the second EMAT from electromagnetic and radio frequency interference.