Ultrasonic hydrophone sensitivity multi-frequency point absolute calibration method

Abstract

The present invention relates to an ultrasonic hydrophone sensitivity multi-frequency point absolute calibration method. According to the method, a single-frequency sine filler pulses are utilized to excite a focusing transducer, so that harmonic signals for calibrating the sensitivity of an ultrasonic hydrophone can be generated; the sound pressure magnitude values of harmonic waves at each order are obtained through using an optical method; and a hydrophone to be calibrated is arranged at the same position of a sound field, and the open-circuit output voltage of the hydrophone to be calibrated is measured, and therefore, the sensitivity of the ultrasonic hydrophone at a plurality of frequency points can be obtained through one-time calibration. Since the focusing transducer is adopted to generate a harmonic sound field which is adopted as the calibration signals, frequent replacement of auxiliary transmitters during a broadband calibration process can be avoided, so that calibration efficiency can be improved; a characteristic that the sound waves of the focusing transducer will form quasi plane waves near the sound focus of the sound waves is utilized, so that a condition that the calibration of the hydrophone is required to be carried out in an acoustic far field is avoided, and therefore, the influence of signal distance attenuation can be reduced, and a signal to noise ratio can be improved; and 3) the optical method is adopted to calibrate the sensitivity of the hydrophone, and therefore, the method is an absolute calibration method.

Description

technical field [0001] The invention belongs to the technical field of measurement and calibration of underwater acoustic sound pressure, and in particular relates to a multi-frequency point absolute calibration method for the sensitivity of an ultrasonic hydrophone. Background technique [0002] Ultrasonic hydrophones are widely used in the measurement and calibration of the output sound pressure of equipment such as medical ultrasound and detection ultrasound. In order to ensure the accuracy of the sound pressure value, it is necessary to measure and measure the sensitivity of the ultrasonic reference hydrophone and the measurement hydrophone. calibration. Usually, there are absolute method and comparative method to calibrate the sensitivity of ultrasonic hydrophone. The absolute method calibration is generally carried out by the reciprocity method of two transducers. During the calibration process, the transmitter-reflection target and the transmitter-hydrophone pair to ...

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Problems solved by technology

The calibration process is cumbersome, each calibration

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