1. Apparatus for determining the thickness of a sample and defect depth using thermal imaging in a variety of plastic, ceramic, metal and other products comprising: a pair of flash lamps positioned at a first side of the sample; an infrared camera positioned near said first side of the sample; a data acquisition and processing computer; said data acquisition and processing computer coupled to said flash lamps for triggering said flash lamps, said data acquisition and processing computer coupled to said infrared camera for acquiring and processing thermal image data; said data acquisition and processing computer processing said thermal image data using a theoretical solution to analyze said thermal image data.