PRELIMINARY ANNOUNCEMENT The 5th PiE Conference will be held in Budapest at the Budapest University of Technology and Economics. The University is co-sponsoring the conference along with Sequoia Scientific, Inc. Assoc. Prof. Sándor Baranya is the local conference co-chair in Budapest. The 3-day conf....
Waterways, Maintenance Dredging, and Contaminated Sediment Removal Dredging is essential for creation or maintenance of navigation channels, as well as for removing contaminated sediments. The contamination of water by dredged sediments is regulated in most developed, and some developing countries....
Sequoia manufactures two instruments based on laser diffraction for monitoring sediments entering hydro turbines. These are the LISST-Hydro and LISST-Infinite. These two produce data on sediment concentration sorted into 3 size classes – fine (<75μm), medium (75 to 200 μm), and coarse (200 to...
The LISST-ABS would reveal rich sediment structure that turbidity misses. For measuring suspended sediments, the use of optical backscatter sensors or other turdibity sensors is widespread. At the same time, it is understood that these sensors respond to total particle area, not volume or mass. In other...
This Note is written for those users who wish to get a deeper understanding of acoustic backscattering and its use in the LISST-ABS. It expands on the very simple page, How LISST-ABS Works. What follows is a description of coherent and incoherent scattering, strength of scattering of sound by particles...
Updated: 4 March 2016. INTRODUCTION: Sequoia’s Acoustic Backscatter Sensor, LISST-ABS is designed to measure suspended sediment concentration at a point. Unlike ADCP’s which may record similar backscatter strength at multiple points (‘ranges’) along acoustic beams, the LISST-ABS ...
This Note shows how the calibration of the LISST-ABS acoustic backscatter sensor and of optical backscatter sensor (OBS) changes when water contains a broad distribution of particle sizes, and why LISST-ABS is inherently superior. Particle size distributions in water are usually not very narrow, i.e....
Scintillation is what makes stars twinkle. It is what causes mirage in deserts or on hot surfaces. It is what causes shimmer underwater in the vicinity of hot vents in oceans. These effects result from temperature fluctuations in air or water. The same effect can occur in a LISST optics cell if not properly...
How to Compute the Mean Particle Diameter from a LISST Volume Distribution [Sequoia, March 26, 2010] In the table below, the computation of the mean particle size from a LISST volume distribution is outlined.Column A is the size class number, from 1-32. Column B is the MID POINT of...
Is there a low velocity threshold for the LISST-SL? Does it need a minimum flow speed in order to sample? What is that? Absolutely! The internal pump in the SL will adjust the intake velocity to match the ambient flow speed in order to make the sample intake isokinetic. However, it is necessary to...