METHOD FOR DETERMINING NONLINEAR ACOUSTICAL PARAMETERS OF LIQUID, SOLID, AND GASEOUS MEDIA

摘要

FIELD: measurement technology; determination of physical and mechanical properties of liquid, solid, and gaseous media in medicine and technical diagnostics. SUBSTANCE: method involves radiation of biharmonic signal at frequencies ω and 2ω into medium under analysis, reception of signal passed through medium, and separation of second harmonic; phase invariance of radiated signal is chosen to be equal to p, amplitudes of radiated signal components are varied at their constant relationship , where value of A is chosen from 0 A 0,61 range, until zero amplitude of received signal is obtained; with sound velocity C_o, frequency ω, amplitude U₀₁(0) of radiated signal component at frequency ω, and distance between emitter and detector x being known, nonlinear acoustical parameter is found from formula , where Z_o is found from equation . EFFECT: improved accuracy and validity of measurement results. 2 cl, 2 dwg