FIELD: fiber-optical communication lines. SUBSTANCE: auxiliary optical fibers whose length is three-five times as long as that of extent of dead space of optical reflectometer are connected in agreement with proposed procedure to both sides of section of optical fiber of communication line via optical connectors. Optical reflectometer operating in time region is connected in turn to auxiliary optical fibers of one or another side of elementary cable section. Attenuation in optical fiber of communication line over assembled elementary cable section on one side is evaluated by characteristic of backward scattering as difference of level of power of backward scattering across output of auxiliary optical fiber connected to nearest end and level of power of backward scattering across input of auxiliary optical fiber connected to distant end. EFFECT: diminished error of determination of attenuation. 2 cl, 3 dwg
