Fay B, Rinker M, Lewin P A
Physikalisch-Technische Bundesanstalt, Braunschweig, Germany.
Ultrasound Med Biol. 1994;20(4):367-73. doi: 10.1016/0301-5629(94)90005-1.
This paper describes a thermoacoustic sensor developed for measurements of the acoustic power and calibration of ultrasonic transducers in the medical imaging and nondestructive testing frequency range. It is shown that the equilibrium temperature produced by ultrasound absorption in an absorbing material and detected by a copper-constantan thermocouple is proportional to the square of the current applied to the acoustic source. It is also demonstrated that the simultaneous measurement of this current and the corresponding equilibrium temperature at a given frequency allow the transmitting current sensitivity of the acoustic source to be calculated. The sensor thus provides a useful and low-cost alternative to the expensive calibration methods such as those based on the reciprocity technique, the planar scanning technique and the radiation force balance. The principles of the sensor's operation are outlined and its construction and characteristics are described. Experimental data in the frequency range of 1-8 MHz are presented and the advantages and disadvantages of the sensor are discussed.
本文描述了一种热声传感器，该传感器是为测量医学成像和无损检测频率范围内的声功率以及校准超声换能器而开发的。结果表明，吸收材料中超声吸收产生并由铜 - 康铜热电偶检测到的平衡温度与施加到声源的电流的平方成正比。还证明了在给定频率下同时测量该电流和相应的平衡温度可以计算出声源的发射电流灵敏度。因此，该传感器为基于互易技术、平面扫描技术和辐射力平衡等昂贵校准方法提供了一种有用且低成本的替代方案。概述了传感器的工作原理，并描述了其结构和特性。给出了1 - 8 MHz频率范围内的实验数据，并讨论了该传感器的优缺点。
