Garcia-Alvarez J, Yañez Y, Prego J L, Turo A, Chavez J A, Garcia M J, Salazar J
Department of Electronic Engineering, Polytechnic University of Catalonia, Comte d'Urgell, 187, SC08, EUETIB, 08036 Barcelona, Spain.
Ultrasonics. 2006 Dec 22;44 Suppl 1:e1093-100. doi: 10.1016/j.ultras.2006.05.106. Epub 2006 Jun 6.
This work presents an ultrasonic sensor for on-line batter monitoring with low-noise design considerations. The density and the compressibility of the batter vary as a function of mixing time and are strongly related to the quality of the final product. Traditionally, a batter sample of a fixed volume is removed and weighted in order to determine its density. This is a time consuming process. Benefits to the industry of on-line measuring techniques include better control of product quality, improving processing efficiencies and reduction in wastage. In this paper low-noise design considerations are accounted for an ultrasonic sensor based on a piezoceramic disk mounted between two reference buffer rods of acrylic resin to measure the acoustic impedance of the batter. Measuring the acoustic impedance changes of the batter its compressibility and density can be monitored. Spurious echoes generated at different parts of the buffer rods boundary strongly affect accuracy and reliability of the measurements, and are considered as noise. The influence of buffer rods geometry on noise level is studied using simulations and afterwards justified experimentally. Design aspects such as buffer rods length and radius, piezoceramic disk frequency and radius are discussed and their influence on noise level is shown. Finally, strategies for optimum geometry design of the ultrasonic sensor are given.
这项工作提出了一种用于在线面糊监测的超声波传感器，并考虑了低噪声设计。面糊的密度和可压缩性会随着搅拌时间而变化，并且与最终产品的质量密切相关。传统上，为了确定面糊的密度，会取出固定体积的面糊样本并称重。这是一个耗时的过程。在线测量技术对行业的好处包括更好地控制产品质量、提高加工效率和减少浪费。在本文中，基于安装在两个丙烯酸树脂参考缓冲棒之间的压电陶瓷盘的超声波传感器考虑了低噪声设计，以测量面糊的声阻抗。通过测量面糊的声阻抗变化，可以监测其可压缩性和密度。在缓冲棒边界的不同部位产生的杂散回波会强烈影响测量的准确性和可靠性，并被视为噪声。使用模拟研究了缓冲棒几何形状对噪声水平的影响，随后通过实验进行了验证。讨论了诸如缓冲棒长度和半径、压电陶瓷盘频率和半径等设计方面，并展示了它们对噪声水平的影响。最后，给出了超声波传感器最佳几何设计的策略。
