Peter Nerman

Abstract

In welding research it is often of great interest to be able to study and document the welding process photographically. Basically, an ordinary camera with film or a CCD/CMOS sensor could be used for these purposes. However, since most conventional welding processes involves an electric arc, this will set special demands on the imaging system. An electric arc is characterised by a very intense radiation in the ultraviolet and visible wavelengths. This radiation can disturb the attempts to image the weld area in the desired way. Different types of filters or ambient light sources could be used in order to reduce the influence of the radiation from the weld arc. The applicability is, however, much depending on the specific purpose with the images and the characteristics of the weld process.This work describes and discusses technical requirements for different arc weld imaging systems including camera, ambient light source and filters. Three main application areas are identified; studies of the welding arc, the weld pool and the material transfer to the weld pool. Typical price levels for different systems are also given.