Investigation Of Air-coupled Piezoelectric Ultrasonic Sensor

Piezoelectric sensor's performance is based on the piezoelectric effect. The sensor is device which carries out the mutual change of acoustic energy and electric energy. The sensor has the advanced merit such as small volume, light weight, compact structure, high natural frequency, high sensitiveness and high signal-to-noise ratio. The sensor has been used widely in many fields such as electro-acoustic, hydro-acoustics, iatrology, military, Especially, metal-piezo ceramics bimorph flexural piezoelectric ceramic sensor clamped along boundary is widely used in the field of manufacture and measure.The paper describes the basic work theory, makes the design scheme according to the demand of the use for the sensor. The materials used during the process, include the PZT materials, the adhesive and other materials. The structure of the sensor is also contrived. And then the sample of the sensor is manufactured in the basis of the work done above. The samples are tested for all the performance and they are accord with the design value. The unqualified samples are analyzed to find the reasons for disqualification. And the measures are taken to improve qualify of the sensors. The principle, virtue and defect, the effect of condition and flow of these conglutinate processing are stated in detail in the paper, especially the conglutinate process is discussed. The selection of the adhesive, the design of the clamp structure and the shape of the load, and the thickness of the adhesive layer are continuous modified and optimized according to the basic theory and performances of the conglutinate process. Finally an optimal conglutinate process parameter is got.