The aim of this paper is to present the first experimental results of a new principle to measure liquid flow by applying a dynamic-weighing approach, which is being implemented in the PTB "Hydrodynamic Test Field" [1]. This new measurement principle relies on a physical analogous model comprising fluid, mechanical and electromechanical elements. They are basic elements representing the model-based approach [3], where appropriate real-time processing and synchronized data acquisition play particularly an important role to reproduce the instantaneous liquid flow rate. Concerning fluid-structure interaction, an exploratory research was conducted to identify the type of forces present in the process, their occurrence and effect upon the system elements to determine the instantaneous flow rate. Some of these system state variables turn out to be measurable and some others, due to their nature, are just assumed as disturbances. For modeling purposes such forces and elements are only possible to be analyzed in terms of their basic form as: sources of excitation, solid and fluid oscillators. First steps are also made to calibrate the output response of the system model in reference to the real system output signal, with the objective to validate the theoretical measurement principle, and to find out the optimum parameter estimation that meets the real process measurand within an acceptable degree of accuracy.
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