| 摘要 |
An apparatus for optically measuring marine conditions comprising a tunnel defining a sampling volume for water, a laser diode line generator for generating a beam of light and reflector means for directing the beam of light across the sampling volume through the water in a direction substantially perpendicular to the direction of flow of the water, and a plurality of photo-sensor elements of similar size disposed for receiving and measuring the intensity of the light beam after passage through the water. The effective size of each photo-sensor element (about 1 mm 2) is greater than the smallest particle to be detected and smaller than the largest organism to be measure. The photo- sensor elements generate an output signal providing an average level representative of turbidity of the water sample, and an rapidly changing attenuated level caused by passage of an organism or particle. Measuring the attenuation of the output signal caused by passage of a particle or organism provides a measure of the size of the particle or organism. By measuring the number of adjacent photo-sensor elements having an attenuated level caused by occlusion by an organism larger than a single photo-sensor element, the transverse size of an organism can be determined. Measurement of the transit time of an attenuated level, indicates the longitudinal size of an organism, or the rate of passage of a particle four providing a measure of the flow rate through the tunnel. Combining transverse and longitudinal size data provides a shape outline of the organism.
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