METHOD DETERMINING FREE SPACE IN VESSEL AND DEVICE FOR ITS REALIZATION Russian patent published in 1999 - IPC

FIELD: determination of volume of substance in closed vessel. SUBSTANCE: method and device provide for high accuracy in determination of free space in vessel without measurement of temperature of substance, for instance, compressed gas, in closed vessel. Method is based on reception and conversion of acoustic vibrations excited in vessel to electric signal and on extraction of signal with resonance frequency of free space of vessel from it. Then it is converted to acoustic vibrations that are used to act on vessel to set active oscillator mode with excitation frequency f_p. Signal frequency f_x corresponding to plane wave propagating along free space of vessel is found. Free space of vessel is determined by expression τ = 4•π•f2x

•l2x/3•f2p,, where l_x is length of vessel. Device for realization of method has external exciter of acoustic vibrations, sensor of acoustic vibrations, amplifier, amplitude selector and adder which input is connected via active low- frequency filter to output of amplifier. Input of amplitude selector is connected to controlled attenuator whose output is linked to power amplifier and output of the latter is connected to external exciter of acoustic vibrations and controlling input of controlled attenuator. Output of adder is connected to computer. EFFECT: high accuracy of determination of free space in vessel without determination of temperature of substance contained in vessel. 2 cl, 3 dwg