[en] As part of a program to upgrade electron beam welding equipment, a micro-computer-based data acquisition system has been built and interfaced with a Hamilton Standard W-2 machine. This presentation will review the design and performance of the system. The practical application of this and similar systems for improved process control will be discussed. Data will be presented relating to the significance of process parameter variations (as monitored by the data acquisition system) on weld geometry and the occurrence of weld defects