| 摘要 |
An improved technique of extracting small samples from a liquid stream, such as a storm sewer, wherein each sample contains a representative portion from all levels of the stream. The relative sample proportions of liquid mass extracted from each elevation of the stream are directly related to the width of the stream at that elevation and the average velocity of the stream at that elevation. An apparatus is disclosed for carrying out this technique wherein a substantially continuous flow pump traverses across the liquid stream in a vertical direction with a rate of speed alongits path that is a function of a product of a reciprocal of the velocity and width functions along the height of the stream.
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