Abstract: In a method for automated, contactless and non-destructive testing of a material joint (4), a dynamic threshold value is varied between a minimum threshold value and a maximum threshold value, with regions of a heat flow dynamics through the material joint (4) being determined which represent values of the heat flow dynamics exceeding the dynamic threshold value. The regions of the heat flow dynamics are examined with respect to an abrupt change in perimeter. An Abrupt change in perimeter occurs if a boundary (7) between a molten zone (5) and a non-molten but still adhering zone (6) of the material joint (4) is being crossed.

Abstract: In a method for the automatic inspection of a welding seam using heat flow thermography, a feature vector is established which represents a time course of a detected heat flow. The feature vector is used to determine, from a series of thermal images, a first characteristic thermal image, which corresponds to a minimum heat flow through an object to be examined, and a second characteristic thermal image, which corresponds to a maximum heat flow through the object, wherein a heat flow directly from an excitation source has already dissipated. A suitable thermal image is used from the series of thermal images to detect and evaluate the welding seam in relation to defects of various defect types, for each defect type, the characteristic thermal images being used as references to determine the respective suitable thermal image.