Sound velocity measuring system based on seafloor sediments

Abstract

The invention relates to a sound velocity measuring system based on seafloor sediments. The system is mainly and technically characterized by comprising a base, a vertical support, a hand crank, a precision ball screw, a linear sliding block, a receiving transducer support, a receiving transducer, a transmitting transducer support, a transmitting transducer, a distance measuring sensor and a measuring instrument, wherein the measuring instrument comprises a signal processing module, a DA module, an opto-coupler isolation module, a power amplifier module, an amplification filtering module, an AD module and a digital display device; the signal processing module is connected with the transmitting transducer through the DA module, the opto-coupler isolation module and the power amplifier module and connected with the receiving transducer through the AD module and the amplification filtering module. The length of a sample is decreased on the premise that the distance measurement accuracy is guaranteed, and the system has the characteristics of reasonable design, compact structure, high measurement accuracy, convenience in use and the like.

Description

technical field [0001] The invention belongs to the technical field of sound velocity measurement, in particular to a sound velocity measurement system based on seabed sediments. Background technique [0002] At present, there are mainly the following two measuring devices for sound velocity measurement of seabed sediments: one is a sound velocity measurement device constructed by the State Oceanic The School of Mechanical and Electrical Engineering of the Industrial University and the South China Sea Institute of Oceanology of the Chinese Academy of Sciences jointly developed a sound velocity measurement device for seabed sediments based on an acoustic wave probe. The above two sound velocity measuring devices are described respectively below: [0003] The sound velocity measurement device built with WSD-3 digital acoustic wave instrument adopts the time delay estimation method of pulse front detection. The frequencies of the transmitting transducers are 25kHz, 50kHz, 100...

AI Technical Summary

Problems solved by technology

The advantages of this measuring device are: the sample length is large, the precision requirements for the length measuring device are low, and the structure is simple; the disadvantages of the measuring device are: the transducer is small, the working frequency is low, the sample length is too large, and the measurement result is that each layer of sediment Combined results of sound velocity, affecting measurements

The disadvantages of this measurement device are: low sensitivity of the acoustic wave probe, additional disturbance to the sample; low frequency, complex sound field in the medium

[0005] In summary, the existing seabed sediment sound velocity measurement device mainly has the following problems: (1) the planar emission transducer is adopted, but the relationship between the acoustic frequency, the emission beam width and the sample size is not considered; the emission beam The width is generally too large relative to the sample size, and the sound wave is reflected at the sample boundary, resulting in disordered received waveforms

(2) The time delay estimation adopts the method of detecting the arrival time of the first wave. On the one hand, due to the influence of the system bandwidth and phase shift, the first wave is easily missed, resulting in errors in time delay measurement; on the other hand, the detection of the first wave Mainly rely on human observation, it is difficult to realize automatic detection

(3) Since the manufacturing process of special-shaped transducers in China is still not very mature, the price and performance of special-shaped transducers still cannot meet practical needs

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