Patent ID: 9194831
Filing Date: 2015-11-24
Classification: G01N,G06T

Abstract:
1. A thermographic test method for locally resolving detection and identification of defects near a surface in a test object, the method comprising the acts of: heating up a portion of the test object such that a thermal disequilibrium occurs between defective regions, affected by defects, and material of the test object that is free from defects, a defect-free surrounding area of a defective region not being heated up or heated up less intensely than the defective region, the surrounding area being located laterally with respect to the surface of the test object; recording a series of thermographic images one after another at a time interval within a heat propagation phase, which heat propagation phase begins when a lateral heat flow with respect to the surface of the test object from the locally heated-up defective region laterally into a surrounding area of the defective region manifests itself, each thermographic image representing a local temperature distribution in a surface region of the test object that is recorded by the thermographic image; determining positionally correctly assigned temperature profiles from the thermographic images, a temperature profile being a locally resolving profile, wherein different locations within the temperature profile are respectively assigned values of a measured variable representing the temperature at the respective location, and each positionally correctly assigned temperature profile being assigned to a same measuring region of the surface of the test object; determining variations over time of temperature values from the temperature profiles for a large number of measuring positions of the measuring region that are recorded by the temperature profiles; and evaluating the variations over time based on at least one evaluation criterion indicative of the lateral heat flow in the measuring region.