[en] A data acquisition system has been designed which will perform on-line weld-parameter sampling. It is a microprocessor-based program controller and calculator. The parameters sampled are beam current, accelerating voltage, focus-coil current, workpiece rpm, and filament voltage. Sampling in analog form occurs in pre-selected angular-rotation increments from 1 to 9 degrees. There are three data printout options: (A) all data displayed; (B) only out-of-tolerance values displayed; and (C) differences between nominal and sampled values in excess of preselected error bands displayed. A magnetic tape cartridge unit allows long-term data storage and easy retrieval. This report is a manual for system operation. It also describes the design--logic principles, circuitry, and programming--in detail