On-line optical monitoring system for arc welding

This paper describes the technical features of four electro-optic sensors for the monitoring of arc welding. The energy released in the process determines the formation of a strongly radiative plasma in the interaction zone. The working principle of the prototype is based on the detection of visible, infrared and ultraviolet emission of the plasma. A discrimination algorithm has been found that allows the characteristics of the weld to be evaluated and to distinguish bad weldings from good ones. (C) 2001 Elsevier Science Ltd. All rights reserved.