According to the NCMS, over the past two decades, thermography has become a widely accepted method for NDI. Thermographic inspection can use either a component’s inherit heat flow (passive thermography) or an induced heat flow (active thermography) to reveal component abnormalities. Passive thermography is used to inspect objects from large distances, while flash thermography (a technique of active thermography) has primarily been limited to close-proximity distances. NCMS’ industry partner, Thermal Wave Imaging (Madison Heights, Mich., U.S.), has developed a method called thermographic signal reconstruction (TSR) that leverages the past success of close-proximity flash thermography and the large distance-to-target principle of passive thermography. The technology is reported to facilitate an unprecedented degree of sensitivity depth range, and resolution of subsurface defects.
Read the full article at Composites World.