This thesis investigates the use of optical coherence tomography (OCT) for non-contact and non-destructive measurement of the geometry and surface topography of welded joints in laser welding. The aim of the study was to evaluate the applicability of OCT to different weld geometries and to determine the influence of measurement and data-processing parameters on the quality of the results. Measurements were performed using an OCT system on structural steel samples, including surface and corner spot welds as well as internal and external corner welds. The effects of the angle of incidence, scanning parameters, and data processing were analysed. The results showed that the weld geometry, angle of incidence, and data processing have a significant influence on the quality of the reconstructed geometry. In more complex geometries, false reflections, shadows, and areas with missing measurement data were observed. It was also found that a lower lateral sampling density can produce artefactual structures on the reconstructed surface. OCT proved to be a useful method for the non-destructive characterisation of the surface of welded joints; however, reliable results require the measurement parameters to be adapted to the geometry of the individual weld.
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