Hess Type Benthic Macroinvertebrate Sampler
This cylindrical freshwater sampler permits quantitative assesment of benthic invertebrates. Based on a design modification by William R. English, it functions in a less complicated, more economical manner than the original Hess sampler.
Modified from an 8″ (20.3cm) plastic tee, it has a conical bag with 8 oz. polyethylene collector at the tip. The bag is attached to the side outlet of the tee.
Using handholds on two sides of the top, the sampler is rotated firmly into stream substrate. The collection bag is oriented downstream. It is secured to the tee with a stainless steel hose clamp. The upstream side is cut open to stream flow, protected from larger floating objects by a 10 x 10 mesh stainless steel screen.
The sampler is 18″ (45.7 cm) high with notched bottom edge. The three cylindrical openings are 8″ (20.3 cm) in diameter. The Nytex collecting bag is 36″ (91.4 cm) long. Three mesh sizes are available to handle a variety of aquatic environments, and replacement collecting bags are available.
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