【摘要】 本文采用2.5MHz的压电换能器,测量了超声在三种不同规格的阶梯形变幅杆中的脉冲回波信号,并且利用数字示波器对信号进行采样,得到了数字化超声回波时域信号,结合傅立叶级数理论和FFT计算方法,再利用MATLAB语言对所测数据进行处理,得到回波信号的波形图和功率谱线图,并对其进行对比分析。研究结果表明:回波信号功率谱线面积在仅细端直径不同,其它条件均相同的阶梯形变幅杆中的传播损耗情况与它的外形有关。这一方法可为超声检测实际应用提供很多有用信息。更多还原

【Abstract】 In this paper,the echo signal of ultrasonic pulse in three step-bar ultrasonic transformers of different shapes is measured by using the piezoelectricity transducer of 2.5MHz frequency.MATLAB language are used to elicit three oscillograms and corresponding spectrum diagrams which are then compared and analyzed.The result of study shows that: the echo signal power spectrum of the areas in the step-bar ultrasonic transformers with different diameters of the narrow only but the same other dimensions and the material are different and with the accretion of the diameter of the narrow.Utilizing the spectral characteristic to carry on the study of ultrasonic echo signal can offer much useful information for measuring practical application in ultrasound.更多还原