Modeling the Response of a Beam Deflection Flowmeter

One of the reasons which impede applications of ultrasonic beam deflection flowmeters is their calibration that usually needs to be performed across the whole range of measured flow rates. In this paper we have aimed to show that given the directivity pattern of ultrasonic transducers, one can design a beam deflection flowmeter with just one transmitting and one receiving transducer and reduce the calibration process of such a device to a single measurement. Moreover, we show how to optimize parameters of the transmitter-receiver setup in order to maximize flow measurement accuracy. It leads us to simple and approximate formulas that relate the size and tilt angles of the transducers to measurement range so that the worst-case measurement error is minimized.