METHOD TO MEASURE LIQUID FLOW Russian patent published in 2014 - IPC G01F1/66 

FIELD: measurement equipment.

SUBSTANCE: method to measure liquid flow passing via a canal consists in the fact that in the canal cross section they select a complex virtual metering surface, which covers fully the entire cross section of the canal, then, in its geometric centre or centres they install an ultrasonic source or sources, which form a group of straight beams, which penetrate the virtual metering arbitrary surface with the specified pitch in latitude and longitude so that it is covered with a grid of points of crossing of each beam with the virtual metering surface, besides, each beam is perpendicular to the surface in the point of crossing. Then for each beam they measure speed of the flow along the beam in the point of crossing with the virtual metering surface in direction of the normal line to the specified surface by Doppler shift of echo signal frequency from the point of space on the virtual metering surface, afterwards integration is carried out for all points of the grid.

EFFECT: increased accuracy of flow rate measurement, provision of service without canal drying and even without shutdown of hydropower plants.

2 cl, 2 dwg