NEWS RELEASE
Cost and Accuracy Comparisons
Mechanical Current Meter System with AquaCalc Versus Other Point Velocity Discharge Systems
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The Van Veen grab is a lightweight sampler designed to take large samples in soft bottoms. Its long lever arms and the sharp cutting edges on the bottom of the scoops, enable it to cut deeply into the softer bottoms. The Van Veen grab sampler is manufactured in two sizes from stainless steel. The weighted jaws, chain suspension, and doors and screens allow flow-through during lowering to the bottom and assure vertical descent where strong underwater currents exist. The relatively large surface area and the strong closing mechanism allow the jaws to excavate relatively undisturbed sediments. When the powering cable is slowly made taut, the chains attached at the top of the release exert great tension on the long arms extending beyond the jaws, causing them to lift, dip deeper into the sediment, and trap material as they tightly close. The stainless-steel, 583 micron, door screens have flexible rubber flaps which, during lowering, are lifted. When the grab settles on the bottom, the flaps fall back and cover the screens completely, preventing any loss of sediment during retrieval.