Sequoia Scientific began operations in 1995 in Seattle (WA) USA,  to develop scientific instruments for environmental monitoring.sequoia


Sequoia deal worldwide, direct in some countries and with agents in others. Most business is in the US with government contracts and research associations.

They produce robust instruments, not just splash proof or watertight; but truly submersible – down to 6000 metres; see the complete range of robust sizers below.

“Sequoia were recently advised by that the United States Federal Interagency Sedimentation Project (FISP) that they will shortly approve LISST Technology, and all instruments that employ it” said Yogesh C. Agrawal, President of Sequoia Scientific Inc. (see below).



FISP is the lead technology laboratory for several US Government agencies involved in sediment studies ( ). A group that includes US Geological Survey (USGS), EPA, USDA Agriculture Research Service, Army Corps of Engineers, Bureau of Land Reclamation, and the US Forest Service. Approval follows several years of testing by FISP and scientists at the US Geological Survey. This approval certifies LISST technology for measurement of particle size distribution and particle concentration by volume (from which mass concentration can by obtained by multiplication with mass density). The widely used sediment samplers traditionally used in the field and developed at FISP are soon to become obsolete and may be replaced by Sequioa’s modern laser diffraction technology.

Links to more information



LISST submersible analyser LDS particle sizing
LISST sediment analysers
Portable particle sizer
ISST-100X product leaflet