Thermo-Electrical Lockin Thermography for Characterization of Subsurface Defects

In the present work, a novel method of infrared (IR) thermography called Thermo - Electrical Lockin Thermography (TELT) was developed for the characterization of subsurface defects in materials and structures. This new IR thermography method is based on the thermal excitation of materials under testing using a Peltier device and appropriate electronics allowing for accurate thermal cycling. Results from using this method were compared with different IR methodologies (i.e. Pulsed Phase thermography). It was found that Thermo - Electrical Lockin Thermography provides not only qualitative but also quantitative results.