Hamid BEHNAM ¹, Shigeo OHTSUKI ¹, Motonao TANAKA²

¹Precision and Intelligence Laboratory, Tokyo Institute of Technology, ²Tohoku Kosei-Nenkin Hospital

キーワード : Diffraction, Phase velocity , Sound speed

The influence of diffraction on values obtained when measuring ultrasound velocity in a sample is discussed here. We show by calculation and experimental validation that the diffraction effect on sound-speed measurement may be considerable when high precision (sound speed precision in the order of 1/1000) is desired. The relationship between diffraction influence and transducer parameters is demonstrated by normalized curves, and a method for compensating for the diffraction effect in measuring transmission time in a sample is presented. The validity of the compensation method is then proved experimentally.