| 摘 要： | The pulse echo overlap method using electrostaic transducers for accurate measurement ofultrasonic velocity in solid media is discussed in this paper.Owing to the advantage of non-contactfor electrostatic transducers,the correction for coupling layer can be eliminated and the correct cyclicoverlap can be easily achieved,thus the performance of the echo measuring system is significanitlyimproved.In this paper the diffraction correction is calculated for the echo measuring system usingelectrostatic transducers,and an ultrasonic velocity measuring instrument and its transducers arealso described.The measuring results for several specimens of glass and aluminium show that themeasuring accuracy of transmission time in this system reaches 1/500 of RF period,that means themeasnring accuracy reaches 0.2 ns at 10 MHz.
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