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Ultrasonic attenuation in pure water: Comparison between through-transmission and pulse-echo techniques

机译：纯水中的超声衰减：通过传输和脉冲回波技术的比较

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The ultrasonic attenuation has been estimated by a variety of methods. However, even if the techniques are accurate, the measurement of this parameter is very difficult because it depends on the conditions of the experiment (frequency, temperature, internal structure of the specimen, artifacts, etc.). Attenuation measurements in tri-distilled and degasified water were made by pulse-echo and through-transmission techniques at 1 MHz, 25°C and 19.7°C. Besides the techniques, a micrometer and a scanner system were used to make the displacements. The attenuation coefficient α is been approximated by the exponential behavior of the ultrasonic signal record along 20 cm. Performance of ultrasound in water was analyzed in two zones, near and far lengths. At near zone, α is highly variant, while at far zone, an average α = -0.04417 np/cm is obtained. The purpose of this work is to compare the through-transmission and pulse-echo techniques to obtain the attenuation coefficient in pure water by the approximation of its exponential behavior.
机译：通过各种方法估计超声衰减。然而，即使该技术是准确的，该参数的测量也很困难，因为它取决于实验的条件（频率，温度，样品，伪像等）。通过脉冲回波和通过 - 透射技术在1 MHz，25＆＃00b0; c和19.7＆＃x00b0; c的衰减测量在三蒸汽和脱气水中进行衰减测量。除了技术，使用千分尺和扫描系统来制造位移。衰减系数＆＃x03b1;通过超声信号记录沿20厘米的指数行为来近似。在水中的超声中的性能分析在两个区域，附近和远长。近区域，＆＃x03b1;是高度变体，而在远区，平均＆＃x03b1;获得= -0.04417 NP / cm。该工作的目的是比较通过其指数行为的近似来比较透过透射和脉冲回波技术以获得纯水中的衰减系数。

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