A.E. Isaev, Yu.M. Aivazian, A.M. Polikarpov FSUE “VNIIFTRI”, Mendeleevo, Moscow regionisaev@vniiftri.ru Al’manac of Modern Metrology № 1 (21) 2020, pages 163–196 On the example of the results of an experiment on measuring the sound reflection coefficient from a material sample, the incorrectness of irradiation of the sample with a spherical sound wave is demonstrated. The … Читать далее Problems of research of acoustic properties of materials by methods of near field