Calibration measurement and application of a dual-probe acoustic measurement method for seafloor sediments

Abstract

The laboratory measurement of the acoustic attenuation coefficient of seafloor sediment poses a significant challenge as it is more difficult to measure with the same precision and convenience as the sound velocity. A novel dual-probe acoustic measurement method (DPAMM) addresses this challenge by simultaneously obtaining the sound velocity and acoustic attenuation coefficient of seafloor sediments, enabling stratified measurements with minimal disturbances. However, issues related to the sensitivity difference between the probes, the diameter of the sample pipe, and the inter-probe blockage can affect the accuracy of the measurement. To address these influencing factors, water was used as a reference standard for calibrating DPAMM. Experimental investigations were conducted to examine the effects of factors such as the diameter of the sample pipe, probe spacing, probe distance from the acoustic source, and probe sensitivity differences. The results revealed a positive correlation between the diameter of the sample pipe and the effective measurement distance, as well as the correction factor for probe blockage. Based on the calibration method described above, sensitivity calibration coefficients and blocking correction coefficients were derived from the experiments. The application of the stratified acoustic measurement of seafloor sediment samples demonstrates the effectiveness of the DPAMM.