Grab Samplers for slow moving river or streams

There are 3 types of grab samplers available

EakmanBottom Grab Samplers

The Ekman Bottom Grab sampler is designed for sampling in soft bottomed lakes and rivers composed of muck, mud or fine peat. As the sampler is lowered, two hinged upper lids swing open to let water pass through and close upon retrieval preventing sample washout. When the sampler reaches the bottom, a messenger is sent down the line tripping the overlapping spring-loaded scoops. Each sampler is constructed of 316 stainless steel including the springs, cables and fasteners. Also available is a 5 ft. and 10 ft. extension handle for operating the sampler in shallow water instead of a cable and messenger. The sampler is also available as a kit which includes stainless 300 gm messenger, 100 ft. cable and carrying case (ordered separately).

Ponar type grab samplers

The Ponar Type Grab sampler is a commonly used sampler that is very versatile for all types of hard bottoms such as sand, gravel and clay. It can be used in streams, lakes reservoirs and the ocean. This modified Van Veen type self-tripping sampler features center hinged jaws and a spring loaded pin that releases when the sampler makes impact with the bottom. It also includes an underlip attachment that cleans gravel from the jaws that would normally prevent lateral loss of sample. The top is covered with a stainless steel screen with neoprene rubber flaps which allows water to flow through for a controlled descent and less interference with the sample. It is constructed of stainless steel with zinc plated steel arms and weights. A simple pin prevents premature closing.

The Ponar style sampler comes in several sizes with the lightweight model (1/8" stainless plate) easily used from a small boat with nylon cable. The heavyweight models (1/4" stainless plate) should be used with a sounding reel.

Van Veen Grab Sampler

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.