A detailed analysis of the MIG spectrum for the development of laser-based seam tracking sensors

This paper presents a detailed series of measurements of the spectrum of the light emitted from a MIG welding arc. This work was done in the framework of a larger project concerning the development of a seam tracking sensor. Detailed measurements and analysis of the spectrum produced from welding arcs have been performed. The measurements extend from the ultraviolet region of the spectrum (150 nm) to the near infrared region (970 nm) and have revealed the presence of many strong emission lines in the spectrum. The results are of great importance for the design of any optical or vision system working close to a welding arc, because the wavelength of the optical system can be selected to be close to a value where the spectrum of the arc causes the minimum interference to the laser light.