Improvement in the signal strength of magnetostrictive ultrasonic guided wave transducers for pipe inspection using a soft magnetic ribbon-based flux concentrator

The magnetostriction means of generation and reception of ultrasonic guided waves is being used for the longrange inspection of pipelines for in-service damage such as corrosion. The generation of higher-strength ultrasonic guided waves in pipes using a magnetostrictive transducer, due to increased magnetostriction using a flux concentrator, is reported in this paper. A soft magnetic ribbon with negligible magnetostriction was used as a flux concentrator in the magnetostrictive sensor. The amplitude of the signal from a sensor with the flux concentrator at a power level of 10% (of the maximum instrument power level) was found to be comparable with the signal obtained from the sensor without flux concentrator at power levels of 50% of the maximum. The effect of the flux concentrator on different magnetostrictive sensors is also reported in this paper.