Abstract
The present work reports results obtained by applying pseudorandom noise injection to the gas metal arc welding process to determine the impulse response of the system (the response to a short pulse of energy). The phenomena having the longest time constants are investigated and it is found that there is a damped oscillation associated with delayed heating of the anode wire stickout. Properties of the oscillation are measured and found to agree with previous research. It is demonstrated that the pseudorandom noise injection technique has advantages in investigating welding processes in which it is desired to determine operating characteristics without significantly perturbing welding.