Most of the phenomenon studied in the welding processes needs a vision system and the arc light emission can create a great barrier. Nowadays, one of the techniques used for visualizing the process, without arc interference, is the illumination of the process with near-infrared laser and the use of optic filters during the image acquisition. Thus, it is important to investigate the welding arc behavior in respect to its light emission within the near-infrared spectrum. Therefore, this work aims to perform a comparative study of the arc near infrared emission in one of the two most used processes: TIG and MIG/MAG, focusing on the influence of welding parameters, such as current and shielding gas. Through a luminous sensor and the use of an optic lens system, experiments were carried out by acquiring the light spectra emitted by the welding arc. It's possible, using the arc results - arc energy value - obtained and following the same methodology proposed in this work, to know the quantity of infrared energy, and its luminosity, needed to overlay the arc during the image acquisition.
Welding; Near Infrared radiation; Vision System