Optimization of buffer rod geometry using MATLAB

Several applications of ultrasonic techniques are limited by the signal-to-noise ratio (SNR). Transducers in these applications usually operate in the pulse-echo mode. Several transducers, especially those for high temperatures, use buffer rods. Interference of the echo signal and noise causes errors of both amplitude and phase measurement of the detected echoes. In this work we discuss the influence of major noise sources as a function of transducer materials, geometry, construction and operating environment. The effects are studied using both experiments and models. Although the results are applied to an ultrasonic density sensor operating in the pulse-echo mode, they are applicable to any pulse-echo mode transducer comprising cylindrical buffer rods. This paper will show how the SNR of the density transducer was improved by careful design to 72 dB.