The 20 mm thick block has been used for 20 mm and 100 mm water paths. For the same reason as previously, only three backwall echoes have been measured with the 20 mm thickness block.
Results are calibrated from a Ø2 mm SDH, located at 28 mm depth and a 50 mm water path. Amplitudes of the surface echo (echo n°0), of the first backwall echo (echo n°1) and of the following backwall echoes are plotted here below in black for experimental measurements, in red for Kirchhoff model results and in blue for specular model results.
Very good agreement is observed between measured results and simulations. The Kirchhoff model slightly diverges from measurements and the specular model from the 8th backwall echo.
The Ascans are represented below in the case of a 20 mm water path for the surface echo and the three measured backwall echoes. The red curve corresponds to the Kirchhoff model, the blue one to the specular model and the black one to measurements.
Signals’ temporal shapes are correctly predicted with CIVA models.
Continue to linear array, 3 MHz, null delay laws
Back to geometrical echoes