Abstract: A method for sensing and controlling the weld quality of gas metal arc welding employs sampling of the welding current and voltage signals and making determinations of the weld quality state based on information embedded in those signals. The signals are processed such that the quality of the weld can be determined and the appropriate steps are taken to respond to the detected quality level. If the quality level is deemed unacceptable the process is terminated and the operator is alerted. The method includes determinations based on the standard deviation of the electrical signal, the summed power spectrum of the electrical signal, and/or the average absolute value of the time derivative of the electrical signal.