METHOD FOR ABSOLUTE CALIBRATION OF EMITTING AND RECEIVING ELECTROACOUSTIC TRANSDUCERS OF ANTENNA UNIT OF ACOUSTIC DOPPLER CURRENT PROFILE RECORDER Russian patent published in 2024 - IPC H04R29/00 

FIELD: acoustic measurements.

SUBSTANCE: method of Doppler profile recorder calibration is based on installing EAT in basin, wherein the calibrated one is placed at a distance from the emitting EAT, equal to a multiple of the length of its near zone, determining the order of variation of discrete excitation frequencies so that values of discrete frequencies form a sequence with the same variation pitch. Then values of discrete frequencies are limited, excitation mode of piezoelectric element emitting EAT is set simultaneously at two frequencies. During calibration, the difference in frequency values is changed from maximum to minimum; electrode diameter-to-thickness ratio is selected for the emitting EAT piezoelectric element, a biharmonic pumping field with a transverse distribution of sound pressure amplitude close to a Gaussian is created in an aqueous medium of a hydroacoustic basin, converting the amplitudes into electrical signals, the amplitudes of which are measured and recorded after gating, filtering and amplification; changing the two-frequency excitation mode of the piezoelectric element of the emitting EAT until the ratios of the amplitudes of the electric signals become equal to numbers whose values do not exceed 0.2; sensitivities are calculated in emission mode and reception mode.

EFFECT: wider frequency range of absolute EAT calibration.

1 cl, 2 tbl, 3 dwg