piezoelectric ceramic transducer admittance circle measuring instrument
The piezoelectric transducer is a key component of the acoustic logging tool, for transmitting and receiving acoustic signals. In the logging tool, the piezoelectric transducer is usually paired use.
Tests show that only when the piezoelectric transducers in the pair having the same resonant frequency and the band width of the received waveform before under the same conditions with a higher consistency.
A lot of practice is confirmed, the transducer logging device directly determines the consistency of the logging is successful.
According to the requirements of practical measurement indicators, based on the ARM controller and a new generation of high-speed analog-digital piezoelectric ceramic transducer admittance circle measurement system designed for measuring transducer characteristic parameters to pick out consistent better transducer.
Design thinking is: LPC2146 control by the controller uses DDS technology --AD9850 sinusoidal signal generator generates a sinusoidal signal frequencies needed by the two-way high-speed ADC ADS2806 sinusoidal signal conversion, and then complete the conversion of data from the controller acquisition and USB transfer, and finally implemented in the host computer for processing the collected data to obtain the curve of the transducer admittance with frequency, and finalize its various parameters.
Software part of the system includes measuring system software and data processing software. Measurement system software is implemented in C ++, the main achievement of the test user initialization data, and systems for data collection, transmission and preservation; data processing software is implemented using MATLAB, using digital correlation, Fast Fourier Transform and sinusoidal fitting of the curve parameters to achieve the three different methods of data processing, the characteristic parameters of the transducer.
Comparison of experimental results showed that: the system admittance circle relative to analog measuring instrument, with a measurement range, high accuracy, high stability and flexibility of the big advantages; expensive relative to foreign impedance analyzer, with targeted, inexpensive advantage; relative to the existing digital admittance circle measuring instrument, with greater measurement range, higher accuracy, test convenience, lower cost.
