TECHNIQUE DETERMINING NONLINEAR ACOUSTIC PARAMETER OF LIQUID, SOLID AND GASEOUS MEDIA Russian patent published in 2001 - IPC

FIELD: measurement technology. SUBSTANCE: technique determining physical-mechanical parameters of liquid, solid and gaseous media can solve problems of medicinal and technical diagnostics. Bi- harmonic wave composed of harmonics with initial amplitudes ν₀₁(0), ν₀₂(0) of oscillatory velocity and frequencies ω, 2ω, is emitted into tested medium, wave transmitted through tested medium is received and second harmonic is isolated. Phase invariant of emitted signal is set equal to π, amplitudes of components of emitted signal are changed keeping constant parameter A equal to ratio of initial amplitude of second harmonic ν₀₂(0) to initial amplitude of first harmonic ν₀₁(0). Value A is selected out of range from zero to 0.61 till amplitude of received second harmonic at point of location of receiver turns equal to zero. Initial amplitude of first harmonic ν₀₁(0) of emitted wave corresponding to this condition is found, nonlinear acoustic parameter is calculated by formula where z₀ is determined from equation where c₀ is velocity of sound in tested medium, ν₀₁(O) is initial amplitude of first emitted harmonic, x is distance between radiator and receiver. EFFECT: enhanced authenticity and accuracy of measurement of nonlinear acoustic parameter. 2 dwg