A computerized gamma-ray scanning device, based on radiation absorption/ transmission principles, has been applied for the investigation of industrial problems. The self designed, developed and applied computer code program ?COLSCAN? is a practical model of gamma scanning for the rectification of chemicals and petroleum distillation columns/ towers in industry. The diagnosis technique is completely non-destructive, in-situ, economical, efficient, accurate and with out any disturbance to the normal operation of the industrial plants. The computerization of data acquisition and analysis further reduces the time and the efforts for the troubleshooting exercises. To simulate the system, various inter-related devices have been developed and operated to acquire data for the precise assessment of malfunctioning conditions in various plant situations which are also outlined in this project research.