Ultrasonic transducer with double sonic path distances and double piezoelectric patches

Abstract

The invention provides an ultrasonic transducer with double sonic path distances and double piezoelectric patches. The ultrasonic transducer comprises a shell which is provided with a ring-shaped boss which is provided with a round groove. A ring-shaped installing groove is formed in the outer wall of the ring-shaped boss. The ring-shaped auxiliary piezoelectric patch is installed in the ring-shaped installing groove. The upper surface of the ring-shaped auxiliary piezoelectric patch is provided with an auxiliary piezoelectric sealing acoustic impedance matching layer. A round main piezoelectric patch is installed in the round groove. The upper surface of the round main piezoelectric patch is provided with a main piezoelectric sealing acoustic impedance matching layer. The inner diameter of the ring-shaped auxiliary piezoelectric patch is larger than the diameter of the round main piezoelectric patch. A fixed distance is reserved between the round main piezoelectric patch and the ring-shaped auxiliary piezoelectric patch in the vertical direction. A first lead hole is formed in the middle of the ring-shaped boss. A first guide wire is arranged in the first lead hole. The first guide wire penetrates the shell and is located outside the shell. The lower portion of the shell is filled with a glue sealing layer. As the ultrasonic transducer can utilize the difference between the sonic path distances of the main and auxiliary piezoelectric patches for accurate measuring to obtain the static sonic speed of media, the flow speed of the media can be measured accurately, and thus the measurement accuracy of an ultrasonic gas meter is improved.

Description

technical field [0001] The invention relates to a transducer, which is a double-sound-path double-piezoelectric sheet ultrasonic transducer. Background technique [0002] Transducers have a wide range of applications, and the structures of transducers used in different fields are quite different. At present, ordinary ultrasonic transducers specially used for ultrasonic gas meters to measure the flow rate, because the gas composition, pressure, and temperature change at any time, therefore, it is extremely difficult to obtain the static sound velocity of the medium, and the accurate acquisition of the static sound velocity of the medium is the key to accurately measuring the gas flow rate. Prerequisites. The single-chip ultrasonic transducer commonly used in the market obtains the sound velocity of the medium by increasing the ultrasonic transmission power to increase the amplitude of the received first wave, sampling the received signal with a high-speed ADC, and then estim...

AI Technical Summary

Problems solved by technology

The disadvantage of this structure is that the emission voltage is high, the power consumption is high, the security is low, and the high-speed ADC is expensive. In addition, the CPU processing must be completed in a short time, which requires high performance of the CPU and low flow rate. The measurement error is relatively large, and the Qmin error is generally around 3%-5%.

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