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Petersen grab
In the Petersen (or van Veen) type of grab, two semicircular buckets of varying sizes are hinged along a central axis. The buckets are held apart for lowering from a ship to the bottom by some form of catch. On striking the bottom, this is released so that on hoisting, the buckets move around on their axis, take a bite out of the sediment, and come together to form a closed container. With this configuration, the rate at which the grab hits the bottom affects the bite, and when the ship is drifting, a poor sample may be obtained if the grab does not hit the bottom vertically.
- 词性: noun
- 行业/领域: 采矿
- 类别 一般矿业; Mineral mining
- Government Agency: USBM
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创建者
- ed.young
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(Milwaukee, United States)