A. Advantages: ultrasonic waves have a high frequency, short wavelength, small bypass phenomenon, especially good directionality, the ability to become a ray and directional propagation and other characteristics. Ultrasonic penetration of liquids, solids, especially in the sun opaque solids, it can penetrate the depth of tens of meters. Ultrasound encounters impurities or interfaces will produce significant reflections to form reflections into echoes, and can produce the Doppler effect when it encounters moving objects. Based on the development of ultrasonic characteristics of the sensor is called "ultrasonic sensor", widely used in industry, defense, biomedical and other aspects.
Two, disadvantages: because the Curie point of piezoelectric materials is generally higher, especially diagnostic ultrasound probe using ultrasonic transducer power is small, the working temperature is relatively low, can work for a long time without failure. Ultrasound probes for medical use have higher temperatures and require separate refrigeration equipment. The sensitivity depends mainly on the manufacturing wafer itself. A high electromechanical coupling coefficient results in high sensitivity; vice versa, low sensitivity.
1, now the ultrasonic transducer frequency are relatively fixed, for example, 40KHz transducer, can only be used in the 38-42KHz, other frequencies are also similar, at present, almost do not see a wide range of frequency range of transducers, for example, 40KHz ~ 500KHz such products;
2, the drive voltage is higher, generally between 100Vp - p to 1500Vp It would be better if there are 3~5V low voltage drive (higher power) sensors;
3, sensitivity, it would be better to be higher;