LASER DOPPLER FLOW RATE METER Russian patent published in 2000 - IPC

FIELD: contact-free remote measurement of flow rates of liquids and gases and of solid and diffusively reflecting objects. SUBSTANCE: laser Doppler meter has laser, cylindrical objective lens, laser beam splitter and lens optically matched, photodetector and electronic unit measuring flow rate. Lens is manufactured in the form of axially symmetric double focus kinoform optical element made of long-focus focusing and short-focus receiving kinoform arranged in same plane in which receiving kinoform is located on optical axis of flow rate meter and focusing kinoform occupies two fragments of total area of receiving kinoform placed in symmetry relative to its axis and limited in area by apertures of laser beams passing through it. EFFECT: reduced measurement error and overall dimensions. 1 cl, 2 dwg