The aim is to provide assistance to ensure that in inert-gas metal-arc welding all the important parameters are recorded and properly evaluated. In this article, the measurement variables and transducers involved are described, together with the protective system used to guard against high-voltage pulses, and advice given on the correct way to connect up multiple measuring devices. Measuring equipment with protected outputs for momentay and effective values, which are easy to operate, help with the further processing of the variables using recording devices or measuring data collection equipment.