Oberflächenwellen-Flüssigkeitssensor

摘要

A liquid sensor has comb-shaped electrodes (12, 14, 16, 18) which are arranged on a piezoelectric substrate (10) and act as interdigital transducers (20, 22) to generate an electroacoustic wave (24) from an emitting transducer (20) to a receiving transducer (22). The number of pairs of fingers of the interdigital transducer and the material of which the electrodes are made are selected in such a way that a surface shearing wave generated by the emitting transducer (20) and a volume shearing wave generated by the emitting transducer (20) have different frequencies.