METHOD OF HYDROPHONES GRADUATION BY THE REFERENCE RADIATOR METHOD Russian patent published in 2017 - IPC H04R29/00 

FIELD: physics.

SUBSTANCE: method of calibrating hydrophones using the standard radiator is proposed. It consists in positioning the graduated hydrophone in a hydroacoustic basin at a distance R from the reference radiator, excitation of the radiator by a signal in the frequency range, emission of an acoustic signal and reception of a direct acoustic signal from the radiator and signals reflected by the basin boundaries, the determination of the frequency dependence of the voltage amplitude at the output of the hydrophone U_h(f), the determination for U_h(f) of the dependence of the Fourier coefficients S(τ), separation by the parameter τ of the Fourier coefficients S_s(τ), relating to the direct and reflected signals, determination of the dependence S'(τ) setting to zero S(τ) of the Fourier coefficients, relating to the reflected signals, determination of the frequency dependence of the amplitude of the output voltage of the graduated hydrophone in a free field U'_h(f) with the inverse Fourier transform S'(τ) and the determination of the sensitivity of the hydrophone to be measured over the free field M_h(f) in the frequency range of the calibration using the formula (1), where P(f) is the frequency dependence of the amplitude of the sound pressure generated by the reference radiator in the free field at a distance R from the radiator, characterised in that the linear-frequency-modulated signal is used as the excitation signal of the radiator, the instantaneous values of the voltage at the hydrophone output are recorded, In-phase U_s(f) and quadrature U_c(f) components of the frequency dependence of the hydrophone voltage, the Fourier transform is applied separately to the in-phase and quadrature components and determine the dependences of S_s(τ) and S_c(τ) coefficients, determine the dependencies S'_s(τ) and S'_c(τ) by zeroing respectively the coefficients related to the reflected signals in S_s(τ) and S_c(τ), determine the in-phase U'_s(f) and the quadrature U'_c(f) the components of the frequency dependence of the output voltage of the hydrophone in the free field by the inverse Fourier transform S'_s(τ) and S'_c(τ), and the frequency dependence of the amplitude of the output voltage of the graduated hydrophone in the free field U'_h(f) is determined by the formula . Further, the sensitivity of the hydrophone calibration is determined by the formula (1).

EFFECT: improving the accuracy.

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