Apparatus and method for quantitative nondestructive wire testing

摘要

An apparatus and method for quantitative nondestructive testing (NDT) of a wire wherein noncontacting ultrasonics is used. A transmitter- transducer coil is held in close proximity of a test wire or tube and high amplitude electrical current pulses are passed in the coil. A magnetic field perpendicular to the longitudinal axis of the wire is applied in the region. As a result of the electrical current pulses in the transducer coil, eddy currents are produced on the surface of the test wire. As a result of the magnetic field applied in the region, these eddy currents lead to Lorentz forces in the wire, which in turn generate corresponding torsional waves in the test wire. These waves speed down the wire and are received by a reciprocal transduction process, by means of a receiver-transducer. The velocity and attenuation measurements of the torsional waves along the axis of the test wire are made precisely and accurately via multiple-transducer setups. The data are interpreted in terms of the material conditions including mechanical defects or flaws in the test wire.