Sequoia Scientific, Inc. has developed a laser diffraction system for measuring sediment properties in rivers and streams, the LISST-SL (for StreamLine). The streamlined body is a minimum drag shape. Twin fins below the body orient the LISST-SL facing upstream before insertion. A pitot static tube on top of the body measures river velocity. The system employs active control of the intake pump that matches river velocity to intake velocity making the sample acquisition isokinetic. Diffracted light is measured in an enclosed electro-optics test section. Data are transmitted up the USGS B-reel to a ‘topside’ Control Box. The detailed size distribution and volume concentration is recovered after data processing.

Depth, velocity, and temperature are stored with each sample. With the included depth data, the system is capable of delivering sediment flux in the river.

The system was first successfully field tested in June 2004.  The first unit was shipped in 2005. For features, details, and preliminary specifications,please download the brochure or email us.