Study of the Measurenet of Acoustic Properties of Film Samples Using Ultrasonic Micro Spectroscopy

研制了用声反射率G和声透射率T测量液体和固体声速的原理和系统。计算了超声换能器与试样不同组合的声反射率G和声透射率T，以确定最佳声频率和试样厚度。仿真结果表明，该方法适用于水中h/lambda<0.1-0.01和空气中h/lambda<0.001的情况，采用综合函数发生器和各种超声换能器的测量系统实现了宽带检测。此外，高精度机械平台使超声波换能器和样品之间的对准精度更高。该系统可实现在线自动测量，并已完成了对各种薄膜及薄膜、箔等薄板材料的实验。与其它方法测定结果的一致性在1%以内。还进行了薄层（~ 1 mm）液体的实验。该方法所需的样品量仅为0.1cc以下。本文还用40 kHz的超声波在空气中进行了薄样品厚度的非接触测量实验。具有微米级厚度的金属箔和纸已经成功地测量，与用微米测量的那些相差在%以内。

Measurement principles and system for sound velocity of liquids and solids using sound reflectivity G and sound transmittance T have been developed. Sound reflectivity G and sound transmittance T were calculated for various combinations of ultrasonic transducer and samples to find the optimum sound frequency and sample thickness. From the simulations, our method can be applied under the condition of h/lambda<0.1-0.01 in water and h/lambda<0.001 in air has been certified, respectively.The measurement system introducing the synthesized function generator and various ultrasonic transducers has established the broad band inspection. Moreover, the high precision mechanical stage enabled the alignment between the ultrasonic transducer and the sample with higher accuracy. On-lined system can be made the automatic measurement.The experiments with various films and thin plate materials such as films and foils has been accomplished. The results have the agreement with those of other method within 1%. The experiments with thin layr (-1mm) of liquids have been also made. In the method, the quantity of sample required in the measurement was only less than 0.1cc.Alternative experiments for the noncontact thickness measurements with thin samples using the same principles as described above, has been made using 40 kHz ultrasonic wave in air. Metal foils and papers having the micro meter order thickness have been successfully measured within some % differences from those measured by micro meter.