Flaw detection is the process of identifying and sizing sub-surface defects in materials. One of the most common techniques to identify defects is ultrasonic inspection where sound waves, propagated through the material, are used to identify such anomalies. The high frequency sound behaves predictably when interacting with surfaces and internal defects.

Flaw detection can be applied in almost any industry from composites and metals used in aerospace, to petrochemical oil and gas pipelines and storage tanks, to power generation including nuclear power. The most common anomalies detected include cracks, voids and porosity in metals, ceramics and plastics in addition to delaminations and disbonds in composites.