During the operation of large industrial installations, a very important task is to maintain the proper technical state. In the event of an emergency, it is vital to locate the place of occurrence as soon as possible. In solving this type of problem, it often helps to apply the methods of measurement associated with ionizing radiation. One of these methods is the gamma scanning. The purpose of this type of measurement is the detection and localization of disturbance of technological processes which may result in incorrect decomposition the fl owing medium and workpiece (sediments, congestion) as well as damage to the internal constructions. A particularly: (i) preventive diagnosis - early detection of installation failure; (ii) rationalization of repairs and renovations - to determine the need to take or not to take remedial action; (iii) quick and precise installation inspections - to gain knowledge of the technical condition and technological installations; (iv) indication of worn parts and posing a threat - diagnostics of the technical condition installation; (v) forecasting the useful lifetime of equipment.