ACOUSTIC COUPLING FROM A FOCUSED TRANSDUCER TO A FLAT PLATE AND BACK TO THE TRANSDUCER

An approximate solution for the acoustic coupling factor (the diffraction correction function) from a focused transducer to a flat plate and back to the transducer is provided. This function is useful for system calibrations where a pulse-echo system or transmit-receive system is used. Numerical solutions are provided for the important case where the hat plate is placed near the focal plane of the transducer. The solution for a hat disk transducer is obtained as a limiting case. Experimental evidence for a focused transducer is provided.