Metzenmacher Michael, Geier Dominik, Becker Thomas
Chair of Brewing and Beverage Technology, TUM School of Life Sciences, Technical University of Munich, 85354 Freising, Germany.
Foods. 2023 May 8;12(9):1927. doi: 10.3390/foods12091927.
An ultrasonic wave mode-based method for density measurement in highly foamed batters was developed. Therefore, a non-contact ultrasonic sensor system was designed to generate signals for batch-wise processes. An ultrasonic sensor, containing a piezoelectric ceramic at the fundamental longitudinal frequency of 2 MHz, was used to take impedance measurements in pulse-echo mode. The ultrasonic signals were processed and analysed wave-mode wise, using a feature-driven approach. The measurements were carried out for different mixing times within a container, with the attached ultrasonic sensor. Within the biscuit batter, the change to the ultrasonic signals caused by density changes during the batter-mixing process was monitored (R = 0.96). The density range detected by the sensor ranges between 500 g/L and 1000 g/L. The ultrasonic sensor system developed also shows a reasonable level of accuracy for the measurements of biscuit batter variations (R > 0.94). The main benefit of this novel technique, which comprises multiple wave modes for signal features and combines these features with the relevant process parameters, leads to a more robust system as regards to multiple interference factors.
开发了一种基于超声波模式的高泡沫面糊密度测量方法。因此，设计了一种非接触式超声波传感器系统，用于为间歇式过程生成信号。使用一个在2 MHz基本纵向频率下包含压电陶瓷的超声波传感器，以脉冲回波模式进行阻抗测量。采用特征驱动方法，对超声波信号进行波模式处理和分析。使用附着的超声波传感器，在容器内对不同的搅拌时间进行测量。在饼干面糊中，监测面糊搅拌过程中密度变化引起的超声波信号变化（R = 0.96）。传感器检测到的密度范围在500 g/L至1000 g/L之间。所开发的超声波传感器系统在测量饼干面糊变化方面也显示出合理的准确度水平（R > 0.94）。这项新技术的主要优点在于，它包含用于信号特征的多种波模式，并将这些特征与相关过程参数相结合，从而在面对多种干扰因素时形成一个更稳健的系统。
