An ultrasonic flowmeter designed according to smart sensors concept

During the last decade, the field of sensors has known a deep reorganization, which is mostly due to the spectacular developments in microelectronics and communication. Among the variety of sensors which take advantage of this approach, the ultrasonic velocity meter used for liquid flow measurements, is ready to provide specific conditions required by the smart sensor concept. This paper first presents a brief outline of the general principle of liquid flow measurements by ultrasonics, and problems of flow measurement. We propose an original ultrasonic method for liquids flow measurement. In this method we use two pairs of ultrasonic emitter-receivers, which are arranged in the proper positions and directions. In this case, to determine the liquid flow velocity, a real time on-line analysis taking into account the geometries of the hydraulic system, is applied to the obtained ultrasonic data. The usefulness of this method is confirmed by experiments that have been carried out. The observed results are presented. Finally, to answer the challenge imposed by the smart sensor concept, we make use of local processing units allowing the implementation of specific and interactive functions, and increasing in this way the global possibilities of the suggested ultrasonic flowmeter