| 摘要 |
An apparatus and method for determining the size and velocity of particles, droplets, bubbles, or the like employing laser light scattering is disclosed. A laser generation means is provided for generating a pair of coherent laser beams. These beams are directed along an axis and are caused to cross the axis at an angle to establish a sample volume. A collection means for sensing the scattering caused by particles, droplets, bubbles or the like within the sample volume is provided. The collected scattered signals are directed onto photo-detectors which are coupled to a signal phase determining means for determining the phase of the scattered signals as the particle, droplet, bubble or the like passes through the sample volume. Sizing means are coupled to the signal phase determining means for determining the size of the particle, droplet, bubble or the like from phase changes and the scattered signal. The velocity of the particle, droplet, bubble or the like is determined using well known laser Doppler anemometry techniques. In addition, the present invention discloses a method to determine the direction of motion of a particle, droplet, bubble or the like passing through the sample volume.
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