Fabrication and test results of a conical acoustic lens

This paper treats the fabrication problems and test results of an acoustic lens built in accordance with the acoustic design presented in an accompanying paper. Specific areas covered include the selection of the internal fluid, the window, construction of the case, sound-absorbing lining, and acoustic test results. With a SOAB sound-absorbing lining, the lens model worked well, giving horizontal beamwidths of6\degand vertical widths of30\deg. There is still a problem of compatibility between the SOAB and the Freon TF lens fluid selected.