Electroacoustic Model Based Pneumatic Fill-Level Measurement for Fluids and Bulk Solids

Abstract

Fill-level sensing remains an important issue in multiple fields of applications, ranging from industrial process control to applications in food storage, construction industry, and public and individual mobility. A main part of the established measurement methods provides satisfactory results only under consideration of a set of preconditions, and – especially in the automotive field – is competitive to modern methods only due to the low sensor cost.Pneumatic level sensing methods have been proposed for fill-level measurement since many years, but usually have the disadvantage of providing accurate results only for perfectly sealed vessels. Hence, these methods cannot be applied to most automotive tank systems as well as to ventilated industrial tank systems. In order to make available the various benefits of pneumatic methods (independence on tank shape, tank orientation, bubble and foam formation, surface structure, ...) for these application fields, we propose a pneumatic gauging method based on an electroacoustic equivalent model approach that is capable of measuring both fill level and leakage extent of a ventilated tank system in one single step.The following sections provide a background about fill-level estimation, an overview of pneumatic fill-level measurement and the results of initial evaluation measurements of the proposed method demonstrating the applicability of the novel method.