METHOD FOR MEASURING LIQUID FLOW Russian patent published in 2023 - IPC G01F1/66 

FIELD: measurements.

SUBSTANCE: invention relates to a method for measuring the flow rate of a liquid and is based on determining the rate of change of the liquid level in a measuring tank of constant cross section. The method includes the following operations: periodically sending ultrasonic probing signals through the liquid perpendicular to the gas/liquid interface, which are generated from a continuous signal of the reference generator; receiving ultrasonic signals reflected from the gas/liquid interface; continuous measurement of the phase shift of the receiving radio pulse relative to the reference oscillator signal; building a graph of phase shift changes in time -Δϕ (t); determination according to the graph of the level difference at the beginning and end of the measuring interval in accordance with the expression: ΔB = [c·(n+((Δф_B+ Δф_E)/ф_UL)-1)]/4f,where: n is the number of extremums on the chart Δϕ (t) detected in the measurement interval; Δϕ_B is the value of the phase shift at the beginning of the measurement interval; Δϕ_E is the value of the phase shift at the end of the measurement interval; Δϕ_UL is the upper limit of measurements of phase shift; c is the speed of sound in the liquid; ƒ is the frequency of the reference signal; measurement of level change time; calculating the level change rate as a quotient of the level difference divided by the level change time; calculating the flow rate as the product of the cross-sectional area of the measuring vessel and the rate of level change.

EFFECT: increase in resolution and an increase in the reliability of measurements.

1 cl, 4 dwg