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研究了一种新型的液体密度声传感器，其结构为压电基片－液体层－各向同性固体板。在特定取向压电基片的背离液体层的表面上有两个叉指换能器，选择恰当的叉指换能器激励频率，可得到较强的声体波响应。叉指换能器激励的声体波在传感器对应的层状结构中来回反射，液体层密度的变化，将从输出叉指换能器的相位或群延时中得到反映。实验结果表明，对于蒸馏水溶液，当其密度相对变化为１０－６时能予以分辨。
A new type of liquid density acoustic sensor has been studied. Its structure is piezoelectric substrate - liquid layer - isotropic solid plate. There are two interdigital transducers on the surface of the specific orientation piezoelectric substrate away from the liquid layer. By choosing proper interdigital transducer excitation frequency, a stronger acoustic wave response can be obtained. The acoustic wave excited by the interdigital transducer reflects back and forth in the layered structure corresponding to the sensor. The change of the density of the liquid layer will be reflected in the phase or group delay of the output interdigital transducer. Experimental results show that, for distilled water solution, when the relative change in density of 10-6 can be resolved.