the invention relates to a short - time arc welding system and method for welding elements on pars . the system is equipped with : a robot having at least one arm that can move in at least one coordinate axis ; a welding head , which is mounted on the arm and on which a holding device for holding an element and a lifting device for advancing and returning the holding device with regard to the welding head are provided , and ; a measuring system for determining the relative position between a part and an element , which is to be welded onto the part and is held by the holding device . the measuring system has a stand , which is mounted on the welding head and which is designed to be , during operation , in contact with the part in order to determine the relative position between the element and the part . the inventive system is also equipped with a storage device , inside of which a number of welding positions can be stored . the measuring system additionally comprises positioning means for positioning the stand with regard to an element held inside the welding head in a multitude of at least two different operating positions , and the measuring system is designed for positioning the stand each time into an appropriate operating position for each stored welding position .