2019 Volume 81 Issue 4 Pages 233-242
Non-destructive estimation of aquatic products’ volume is important for efficient feed utilisation, and for determining the appropriate time for landing. To enable this, we propose a double cavity underwater Helmholtz resonator for precise aquatic products’ volume estimation. The fundamental principles were developed and the resonator consisting of the generating cavity and the sample cavity was fabricated. By attaching an underwater speaker to the generating cavity, sweep sound was generated and captured using the speaker’s impedance technique. Air, which is less dense than water, was inserted into the sample cavity to mimic aquatic samples of increasing volume. Resonance frequency decreased as air volume increased. A high linear correlation with an R2 of 0.99 between the actual and predicted volume was obtained.
