Phase sensitive modulation thermography and its applications for NDE

The advantages of phase sensitive modulation thermography (also called lockin thermography) are here illustrated together with some applications of non destructive evaluation (NDE) on advanced materials and large structures. Lockin thermography has shown to be a versatile tool for rapid inspection of large surfaces and detection of defects in materials where other NDE techniques are not able to give good results. Besides this, the phase angle image eliminates many undesired effects like inhomogeneous distribution of surface heating that make images obtained with pulse thermography difficult to interpret.