the visual observation of objects, phenomena, and processes in optically opaque bodies and mediums and under conditions of poor visibility. The task of introscopy is the detection and identification of various deviations from the predetermined properties (parameters) of products, bodies, and mediums and the study of the phenomena and processes in translucent and opaque mediums. Some methods and means of introscopy that are used for nondestructive testing of industrial products and materials are similar to the methods of flaw detection and, in particular, of X-ray inspection. However, a number of problems associated with the visual observation of objects under water, deep within rocks and glaciers, in fog, or during a heavy snowfall can be solved only by methods of introscopy.
Introscopy is accomplished using methods for visualization of the spatial distribution of various types of penetrating radiation and fields: elastic oscillations of the medium (at frequencies ranging from 10 hertz to 1000 megahertz); the entire known range of electromagnetic oscillations (from hard gamma radiation to low-frequency oscillations); magnetostatic, electrical, and gravitational fields; and fluxes of elementary particles (such as neutrinos and neutrons). Gamma-X-ray introscopy uses gamma and X radiation, which penetrates fluid and solid objects of arbitrary form and of any chemical composition and temperature. The high resolution of X radiation makes it possible to observe extremely small nonuniformities in opaque materials. Infrared introscopy is based on the ability of many substances to absorb and reflect infrared rays according to their chemical composition, molecular structure, and state of aggregation. The propagation of infrared rays conforms to the laws of light optics; invisible infrared images that can later be converted into visible images are formed by means of optical devices. Methods of direct observation of the distribution of fields, such as magnetic or electric fields, are based on magneto-optical phenomena. Ultrasonic introscopy is based on the ability of ultrasound to penetrate metals, plastics, living tissue, most building materials, and optically opaque fluids. In radio introscopy electromagnetic waves from fractions of a millimeter to several meters long are used as the penetrating radiation. Radio waves of the millimeter and centimeter bands are most often used to produce images of very small objects. Radio introscopy makes it possible to “see” into the center of rocks and glaciers and to compile charts of the radio emissions of the earth’s surface and cloud cover.
REFERENCESKrylov, N. A. Elektronno-akusticheskie i radiometricheskie metody is-pytanii materialov i konstruktsii. Leningrad-Moscow, 1963.
Oshchepkov, P. K., and A. P. Merkulov. Introskopiia. Moscow, 1967.
K. M. KLIMOV