OPTICAL FLOW METRE FOR MEASURING FLOW OF GASES AND LIQUIDS IN PIPES Russian patent published in 2009 - IPC G01P5/26 G01F1/704 

FIELD: physics; optics.

SUBSTANCE: invention relates to laser double-point optical flow metres and is chiefly meant for use in natural gas transportation. Two optical waveguides (33, 34) from a laser source transmit light in form of two separate beams through a window (19) in the wall of a pipe. A telocentric optical system (28) focuses the beams on two focal points lying along the axis of the pipe and at a known distance from each other. Light which is scattered by particles carried by the stream of the fluid passes through an aperture (27) behind a second window (20) in the wall of the pipe to two optical waveguides (49, 50) and is focused on the surface of a photodetector. A non-transparent shade (44) blocks non-scattered beams (23, 24) of the emitted light. By measuring the lag time between detected signals using an electronic signal processing device, the speed (flow) of fluid can be determined.

EFFECT: invention increases sensitivity of measurement in streams contaminated with fine particles, and also enables determination of the shape and size of the scattering particles carried by the stream.

28 cl, 17 dwg