Suspended sediment concentration (SSC) sensor
LISST-25X™ Sequoia Scientific

LISST-25X marks a generational advancement in the measurement of suspended sediments. Unlike all prior sediment sensors, optical or acoustic, the LISST-25X maintains its calibration over a 200:1 range of particle sizes. It has been shown that when evaluated with particles of a broad range of sizes and of several types - manmade spheres or natural terrigenous, or marine sediments from several locations - the LISST-25X held calibration to within a factor of 2 whereas transmissometer calibration changed by 2 orders of magnitude

The LISST-25X uses a newly patented concept. It employs a collimated laser beam to illuminate particles, and a specially shaped focal plane detectors behind the receiving lens. A comet shaped detector senses volume concentration of particles, holding calibration over a 200:1 size range. A second detector measures the area concentration. A Sauter Mean Size of sediments is provided from the ratio of these two outputs also.