Patent ID: 8471207

Claim:
A method for the automatic inspection of a welding seam using heat flow thermography, in which an object, which is to be examined, with a welding seam is provided, wherein the object is excited by means of at least one excitation source, and the heat flow produced by the excitation is detected in a series of thermal images using at least one infrared sensor, wherein feature vector (W(N)) is produced, which is a time course of the detected heat flow wherein a first characteristic thermal image (T 1 ) is dynamically determined from the series of thermal images using the feature vector (W(N)), and the first characteristic thermal image (T 1 ) has a minimum heat flow (W min ) through the object, and a second characteristic thermal image (T 2 ) is dynamically determined from the series of thermal images using the feature vector (W(N)), and the second characteristic thermal image (T 2 ) has a maximum heat flow (W max ) through the object, and wherein a heat flow directly from the excitation source to the characteristic thermal images (T 1 , T 2 ) has already dissipated, if it is apparent from the series of thermal images, and a suitable thermal image (T F1 , T F2 , T F3 , T F4 ) from the series of thermal images is used to detect and evaluate the welding seam with respect to defects of various defect types, for each defect type, the characteristic thermal images (T 1 , T 2 ) being used as references to determine the respective suitable thermal image (T F1 , T F2 , T F3 , T F4 ); wherein a thermal image, which was detected before the first characteristic thermal image (T 1 ) and has a maximum heat flow (W max ) of the excitation source is used for detecting defects of a second defect type as a suitable thermal image (T F2 ), the defects of the second defect type being continuous defects of the welding seam.