METHOD FOR MEASURING THE FLOW RATE OF FLUID MEDIA AND AN ULTRASONIC FLOWMETER (EMBODIMENTS)

摘要

The inventions relate to measurement engineering and can be used in measuring devices for measuring the flow rate of a fluid using ultrasound. The essence of the invention is as follows: an ultrasonic wave is emitted both along a flow path and counter to said flow path by piezoelectric transducers 2(10) and 3(11). The received ultrasonic wave from the piezoelectric transducers 2(10) and 3(11) is converted into an electric signal. On the basis of the positive half-waves of the electric signal, a comparator 6(14) forms a sequence of rectangular pulses having the same amplitude and containing information about the transmission time of the ultrasonic waves in both directions. The ultrasonic wave is converted into a sinusoidal electric signal so that the first half-wave thereof is always positive. In a first embodiment of the flowmeter, the electric signal is inverted after having been transmitted via a receiving-amplifying path (5). In a second embodiment, one of the piezoelectric transducers (10, 11) is connected to the corresponding inputs-outputs of a controlled switch (12) by an electrode, the polarity of which is opposite to that of the other transducer. The technical result is an increase in the accuracy with which the flow rate of fluid media is measured by eliminating error caused by the Doppler effect.