CPC G01N 15/10 (2013.01) [G01N 2015/1027 (2024.01); G01N 2015/1029 (2024.01); G01N 2015/103 (2024.01)] | 15 Claims |
1. A velocimeter/nephelometer for measuring the three-dimensional velocity and/or size and/or shape of a particle, comprising:
a two-dimensional platform;
a set of three laser interferometers mounted to the platform, each operable to produce a laser beam having a fringe pattern;
wherein the laser interferometers are arranged such that the laser beams intersect within a volume of observation within the inner area of the platform;
wherein a first two of the laser interferometers are arranged around the platform such that they are spaced ninety degrees apart, and are operable to produce like-oriented fringe patterns with an angular separation between the propagation direction of their beams being ninety degrees;
wherein a third one of the laser interferometers produces a bean with the fringe pattern oriented orthogonal to the fringe patterns of the first two of the laser interferometers;
a set of at least three photodiode detectors mounted to the platform; and
wherein each detector is positioned and filtered to detect light from an associated laser interferometer, the light having been scattered by a particle as the particle passes through the volume of observation.
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