Abstract
It is necessary to understand the behavior of arc that appears in actual welding operation and it makes the welding advanced and intelligent operation. Moreover, the technique is preferred that it is simple and robust. In this research, we examine the technique to presume the welding situation by evaluation of the relation between the welding sounds and the behavior of arc current and voltage. Experiments have been performed under the conditions that the components of shielding gas, their mixture ratio and the polarity of electrode were changed respectively. Some findings were obtained by comparing the sound and image information obtained by each situation of welding.
