Defect mapping of pipeline and plate structures has been performed using ultrasonic, eddy current, and laser methods. However, all of these methods require access to the defect location as a local inspection method. Using a sector probe, MsS guided wave can perform defect mapping without access to the defect location and can detect defects located at inner and outer surface of the structure.

The figure above depicts a 24-inch-OD pipe with a MsS probe on the top of the pipe and the corresponding 3-D mapping plot. The 3-D plot shows the severity of the defects with a spectrum of colors: green, cyan, blue, magenta, and red. The red color represents the highest reflection from the defects and green the least. The mapping was done with 1-cycle, 128-kHz center-frequency, and 4-inch-long MsS sector probe for high spatial resolution. This guided wave mapping of defects can be applied to inspect simple pipe support, welded pipe support, precast concrete pipeline supports, hold-down/anchor straps, saddle support for horizontal pressure vessel, insulated tank wall, soil-air interface, concrete air interface, insulated elbow area, insulated T-joint, and complex geometric area