Defect detection with CCD-spectrometer and photodiode-based arc-welding monitoring systems

In this paper a detailed study on the ability of a system based on photodiodes to detect a wide variety of weld defects is presented. Narrow optical filters have been included within the setup to analyse their influence in the resulting monitoring signal and a direct comparison to the performance of the spectrometer has been also considered. The results obtained during the experimental tests indicate that the use of these filters clearly improves the resulting monitoring signals provided by the photodiodes, suggesting that a photodiode-based setup could become an alternative to the employment of spectrometers in some particular scenarios.