Techniques to measure liquid level in containers and vessels non-invasively are of great interest for the manufacturing, chemical industries, and energy sectors. Most commercial solutions use invasive techniques, which are not always practical and can lead to unsafe conditions when measuring devices encounter high pressures or hazardous chemical contents. In this study, a portable, non-invasive acoustic liquid level identification technique is developed. The technique relies on comprehensive analysis of acoustic guided wave modes in the container walls and their coupling to liquid contents to determine the optimal sensor separation distance and excitation signal characteristics, resulting in liquid level determination with high accuracy and precision. First, dispersion characteristics of guided wave propagation in container walls in contact with a liquid boundary are studied in detail. Based on the dispersion analysis a general-purpose short-range liquid level detection methodology is developed. The developed methodology is then validated using numerical wave propagation simulations and experiments on various metal containers with different physical characteristics, illustrating the versatility of the method. Compared to existing techniques, which are optimized for specific applications, the proposed method, due to its short range and non-invasive nature, has the potential for universal applicability on virtually any container, irrespective of its shape, size, wall-thickness, and whether it has any internal components.

中文翻译：

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用于容器液位测量的非侵入式短距离声学技术

非侵入式测量容器和容器中液位的技术引起了制造业、化学工业和能源部门的极大兴趣。大多数商业解决方案都使用侵入式技术，这并不总是实用，并且当测量设备遇到高压或危险化学物质时可能会导致不安全的情况。在这项研究中，开发了一种便携式、非侵入式声学液位识别技术。该技术依靠对容器壁中的声导波模式及其与液体含量的耦合的综合分析来确定最佳的传感器间隔距离和激励信号特征，从而实现高精度的液位测定。首先，详细研究了与液体边界接触的容器壁中导波传播的色散特性。基于色散分析，开发了一种通用的短程液位检测方法。然后使用数值波传播模拟和对具有不同物理特性的各种金属容器进行实验来验证所开发的方法，说明该方法的多功能性。与针对特定应用进行优化的现有技术相比，所提出的方法由于其短程和非侵入性的性质，具有普遍适用于几乎任何容器的潜力，无论其形状、尺寸、壁厚和形状如何。是否有任何内部组件。