Influence of weld imperfection on short circuit GMA welding arc stability

Monitoring of welding process can play important role in on-line quality control of the GMA welding process. It is very important to find a quick and safe method of analysing data recorded during monitoring. Two signals: momentary arc power and momentary arc resistance were included in the analysis and the results of analysis were compared with the results of statistic analysis of welding current and welding voltage. Sensitivity of mean value and variance of signals to artificial disturbances of welding arc was tested. The results show that it is possible to detect imperfections related to phenomena that take place in welding arc and affect the gas shield of the welding arc or the length of wire extension.