Sequoia Scientific

Product Overview

Submersible and Field Instruments for Measuring Particles and their Properties



Our instruments at 1. Grand Canyon USA, 2. Three Gorges Dam, China; 3. Venice lagoon; 4. Deepwater Horizon oil spill monitoring; 5. Japan Fukushima monitoring; and 6. Danube in Hungary.


Welcome to Sequoia Scientific, Inc.

In 1995, Sequoia Scientific, Inc. introduced the world’s first submersible commercial instruments for particle sizing based on laser diffraction. These LISST instrument systems are self-contained, compact, programmable, battery-powered, and they hold calibration for life. The brand name LISST derives from Laser In-situ Scattering and Transmissometry. Recently, instruments using holography and acoustic backscatter have been introduced under the LISST brand. These instruments are used for measuring particles, and for measuring optical properties of water. We offer a condensed view of the entire instrument line by application below. Still not sure? Please contact us.

Sediment and other Particle Sensors


For the Natural Marine-Aquatic Environment

LISST-200X:  Supersedes the original LISST-100X. Measures particle size distribution (PSD), concentration.

LISST-Deep:  Deep ocean use, measures PSD and concentration, similar to LISST-200X.

LISST-ST:      Measures the settling velocity of particles binned into 8 size classes.

LISST-ABS:    A high-frequency acoustic backscatter instrument for measuring particle concentration.

LISST-Portable|XR: World’s sole hand-portable particle PSD and concentration sensor.

LISST-HOLO:  A submersible holographic camera. Records holograms for subsequent reconstruction of particle images, and to compute PSD and concentration.

Reservoir Siltation and River Sediment Transport

In addition to all of the above instruments, the following are specific for rivers:

LISST-SL               Replacement for point-integrated or depth-integrated samplers. Profiles river columns for PSD, Concentration, Depth, Temperature, and velocity.

LISST-StreamSide     A shore-mounted instrument for PSD and Concentration from a pumped stream.

Drill Mud Size Analysis for Oil and Gas industry

LISST-Portable|XR   This instrument is most popular for on-site analysis of drilling muds.

Protection of Hydropower Turbines from Sediment Abrasion

LISST-Hydro         Used to measure sediment PSD and Concentration when concentration is below a few 1000’s ppm. Generates alerts and warnings when hazardous conditions arise.

LISST-Infinite       Automated dilution version of LISST-Hydro measures higher concentrations. Generates alerts and warnings when hazardous conditions arise.

Instruments for Marine Optics

LISST-200X          Measures beam attenuation coefficient, and small-angle volume scattering function. (VSF)

LISST-VSF            Measures beam-attenuation, VSF, and depolarization, P­12 from 15 to 150o.

LISST-STOKES    Measures beam-attenuation, small forward angle VSF, and depolarization, P12.

Radiative Transfer Software

Our HYDROLIGHT and ECOLIGHTsoftware products are de facto standard for computing light propagation in the sea via radiative transfer modeling.

We do particles. If you have a need, please surf the pages from here, or contact us.