This paper describes the development of a fully automated instrument that measures critical spray characteristics of liquid atomizers via an optical, direct-imaging method. The system uses a gas laser as the illumination source to backlight a liquid spray and a lens system to project an image of silhouetted droplets on a vidicon tube. A microcomputer performs all system control and data analysis as well as diagnostic functions. A data acquisition front-end supplies droplet data to the computer in real time. Pertinent system design issues are discussed, and the resulting design choices are described. When fully operational, the cycle time for sample hardware testing, data analysis, and report preparation is expected to be under 30 min. The optical portion of the system has already been used successfully to visualize and videotape numerous sprays.