Book Description: This research text describes on an engineering level how a physical sample may be modeled as an equivalent electrical circuit using the SPICE circuit simulator. The SPICE-based model is then used to adequately locate cracks on the simulated sample based upon the electro-thermal relationships between time delay and voltage (temperature) magnitudes between the model and physical sample. This experiment demonstrates how SPICE may be used as a useful simulation tool in the analysis of defects and for investigating non-intrusive thermal diagnostic response.