New Possibilities of Testing the Darkening of Automatic Welding Filters as Expressed by Switching Time

Welders constitute an occupational group that is particularly exposed to high-risk hazards arising from harmful radiation emitted during welding, including ultraviolet (UV) and infrared (IR) radiation, as well as visible (VIS) radiation, whose high intensity causes glare. Effective protection of the eyes and face is provided by welding shields equipped with automatic welding filters (AWFs), which activate automatically upon arc ignition. Their switching time is the most important protective parameter, as it has a direct impact on the user’s visual health. The objective of the work is to present a novel test stand for determining AWFs switching and holding times, which provides advanced possibilities for evaluating all types of AWFs. Until now, performance and safety levels have been determined based on numerical values: switching time and hold time. For the first time, it is possible to analyze the darkening and clearing phenomena over time with an interpretation of graphical results. Importantly, it is possible to analyze the symmetry of filter properties, using two measurement channels, which is crucial for binocular and curved (panoramic) AWFs. The results obtained for two types of AWFs mounted in goggles with a one-piece and a binocular visor differ from each other. Switching time differences between the left and right measurement channels were about 6–7% for the one-piece visor goggles (G1) and about 3–4% for the binocular goggles (G2). The dispersion of results confirmed the importance of the two measurement channels, which was not previously practiced. The test stand, designed in accordance with the requirements of the new European standards (EN ISO 18526-2:2020, EN ISO 16321-2:2021), can be used for prototyping and for AWF certification purposes.