US BL-84 Sampler

HIF/FISP Part # 4103014

The US BL-84 is a cable-suspended bedload sampler used to collect samples from streams that cannot be waded. The sampler consists of an expanding nozzle mounteda frame, and a sampler bag. The sampler design enables collection of particle sizes larger than the bag mesh opening and smaller than 1.5 in (38 mm) at stream velocities up to 9ft/sec. The sampler has a 3 by 3 in entrance nozzle and an area expansion ratio (ratio of nozzle exit area to entrance area) of 1.4. A 295 in2 polyester mesh sample bag 18 in long with mesh openings of 0.25 mm is attached to the rear of the nozzle assembly with a rubber “O” ring.

The US BL-84 is constructed of stainless steel and aluminum, weighs 32 lbs and is 36 in long. It is equipped with tail fins that orient it into the stream-flow. The sampler must be supported by a steel cable and reel to be lowered into a river or stream for taking a bed load sample. At high stream velocities, a tether line may be required. HIF Repairable.

Where and how the sampler is deployed in the field is as important as the fundamental design of the sampler. Additional information about how to properly use this sampler can be found in the following references:

Edwards, T.K., and Glysson, G.D., 1999, Field Methods for Measurement of Fluvial Sediment: U.S. Geological Survey Techniques of Water Resources Investigations, book 3 chapter C2, 89 p.

A copy of operating instructions at located at (http://water.usgs.gov/fisp/docs/Instructions_US_FL-84_990507.pdf) and is provided with each sampler.

Associated Components

4109002 BAG FOR BL-84 SAMPLER