Study On Consistency And Matching Of Piezoelectric Transducer

since the 1970s.As a key component ofUltrasonic flow meter is a kind of non-contact instrument,which has been widely used ultrasonic flow meter,the piezoelectric transducer is often encountered with poor consistency and hard to matching in practical engineering applications.Therefore,this paper studies the consistency and matching work of the transducer,aiming at providing a method for quantitatively evaluating the consistency of transducer,so as to improve the matching efficiency,mainly including the following contents:(1)Principle Analysis.According to the working principle of time difference ultrasonic flow meter,it is proved that the measurement accuracy of ultrasonic flow meter is influenced by the consistency of transducer.(2)Model Derivation.The complete signal transmission process of transducer is analyzed theoretically.Introduce the transfer function of the generation,transmission,and reception of sound waves in turn,which lays a theoretical foundation for the follow-up transducer consistency evaluation method.And a detailed measurement method for related parameters is given.(3)Consistency Evaluation Method.The consistency of the transducer including steady state and transient characteristic two aspects:the steady state property describes the change of the electrical impedance of the transducer with the frequency,and can be evaluated by the admittance circle graph method or the transfer function method.The transient characteristic refers to the electrical signal output by the transducer in pulse-echo,and the final matching of the transducer is realized by comparing the similarity of the electric signal waveform between different transducers.In this paper,in order to solve the problem of the measurement of signal waveform similarity,the correlation coefficient method and morphological characteristic method are presented.(4)Transducer Test.Firstly,the effectiveness of the transducer consistency evaluation method is verified through the matching test of the transducer.At the same time,it is found that in the measurement of the similarity of signal waveform,the method of morphological feature is more reasonable than the correlation coefficient method.Secondly,test the performance of the transducer under different temperature,such as:the best working frequency,signal amplitude and the weighted slope distance through temperature test,and the influence of temperature factors on the performance of transducer was studied.