FIELD: optics. SUBSTANCE: energy of infrared and visible regions of spectrum is directed through container into intake chamber equipped with matrix sensitive element controlled by computing unit ( CCD pickup ) which absorbs light energy in visible and infrared ranges. Lateral polarizers are positioned on opposite sides of container, they function with use of light energy in visible part of spectrum blocking passage of visible light into chamber in absence of any changes of stresses in container which alter polarization of visible light energy passing through container. On the other hand, polarizers act weakly or do not act at all on light in infrared region which creates background of gray color and normal intensity in intake chamber. Thus incidence of visible light on intake chamber because of changes of stresses in container is manifested in the form of bright signal against normal gray background. as blocking of light in infrared region caused by change of degree of transparency of container is displayed in the form of dark signal or spot against normal gray background. EFFECT: increased efficiency, convenience and reliability of method and facility. 15 cl, 3 dwg
