Ultrasonic transducers for gas flow meters

摘要

The invention relates to instrument engineering and can find application in ultrasonic instruments for various purposes, for example ultrasonic flow meters liquids and gases, level gauges etc. The device is a round bar of piezo coated with a thin layer of a nanocomposite material based on a high-pressure polyethylene having embedded therein nanoparticles of metals and metal oxides. In the propagation of acoustic waves in a cross section of such a waveguide is formed by mechanical displacement field defined structure. If the waveguide is placed in a gaseous environment, it may face a source of acoustic waves in a gas. With the piezoelectric transducer in the structure "the piezoelectric cylinder - nanocomposite polymer layer" excite cylindrical compression zero order wave C ₀ or C ₁ with the corresponding values of the selected frequency RF generator. The end face of the cylindrical acoustic conductor is in this case a source of bulk acoustic wave emitted into the gaseous medium. The technical result is to narrow the radiation pattern radiated into the gas volumetric wave and the increase in its intensity along the axis of the radiation pattern by coating the outer cylindrical surface of the radiator low impedance layer of a nanocomposite material based on a high-pressure polyethylene having embedded therein iron nanoparticles with a mass concentration of 2%. As mentioned above the converter, the compression wave excitation may be used a piezoelectric plate with electrodes or system of annular strips which are electrically connected through one (the analog interdigital transducer).