New algorithm for improvement of sizing accuracy of defect depth in MFL type nondestructive testing

MFL (Magnetic Flux Leakage) type NDT(Nondestructive testing) has been applied for the highly efficient inspection of defects underground gas pipelines. From the measured sensor signals, it is necessary to decompose or estimate the size and shape of defects for the maintenance of underground pipelines. In the maintenance, the depth estimation is the most important procedure for the management of safety accident. This paper focused on the enhanced algorithm for the depth sizing in various defects by presenting the decouple algorithm, and estimated results are compared with measured signals.