Sequoia Scientific, Inc.
Sequoia Scientific, Inc. has been the global leader in technologies for submersible and field measurements of suspended particles, and particle size distributions.
- +1 (855) 753-3313
- info@sequoiasci.com
- 2700 Richards Road
Suite 107
Bellevue, WA 98005
United States of America
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Product
FloControl Instruments
FlowControl-Sub
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FlowControl-Sub is a microprocessor-controlled fully submersible 3-way valve system for use in flow-through applications on profiling platforms such as for example CTD’s or profiling floats.
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Product
Deep Submersible Particle Size Analyzer
LISST-Deep
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The LISST-DEEP instrument obtains in-situ measurements of particle size distribution, optical transmission, and the optical volume scattering function (VSF). Using a red 670nm diode laser and a custom silicon detector, small-angle scattering from suspended particles is sensed at 32 specific log-spaced angle ranges. This measurement is post-processed to obtain sediment size distribution, volume concentration, optical transmission, and VSF. The electronics and optical configuration in the LISST-DEEP are very similar to Sequoia’s workhorse, the LISST- 100X. However, because of the extreme difficulty associated with keepingalignment under high pressure, the LISSTDEEP hardware design is radically different from the LISST-100X. This allows the LISST-DEEP to be deployed down to 3000 m and obtain reliable measurements of the in situ particle size distribution and volume concentration in waters with optical transmission up to 98.5%.
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Product
Radiative Transfer Numerical Model
HydroLight
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The HydroLight radiative transfer numerical model computes radiance distributions and related quantities (irradiances, reflectances, diffuse attenuation functions, etc.) in any water body.
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Product
Acoustic Backscatter Sensor
LISST-ABS
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The LISST-ABS is a fixed-point monitoring sensor. It uses a new and novel technique to internally compensate for geometric beam spreading and attenuation, yielding de-attenuated backscatter signal strength. It is held pointing into flow for low drag.
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Product
Portable Particle Size Analyzer
LISST-Portable|XR
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Truly portable – completely self-contained with built-in data logger, processor, rechargeable battery, and 7” color touch screen display.Particle Size Range 0.35 to 500 micronsPumped and recirculating mixing chamber that keeps large and heavy particles suspended.Shock mounted optics block that can withstand the rigors of field use.A built-in ultrasonic probe for complete sample dispersion.Touch panel allows for easy SOP programming, sample analysis and display of data without a PC.Multiple Mie models as well as Fraunhofer model available for inversion, selectable from the touch panelAll data-processing is performed on board and stored in ASCII format. No post-processing necessary.Outputs: Total volume concentration, mean size, standard deviation, optical transmission, D5, D10, D16, D25, D50 (median grain size), D60, D75, D84, D90, D95, D60/D10 (Hazen uniformity coefficient), particle surface area, silt fraction, silt volume, size distribution, battery voltage, sample notes.Based on the laser diffraction principle. Compliant with ISO-13320-1 standard.
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Product
Optical VSF Sensors
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The optical Volume Scattering Function(VSF) is an ‘inherent optical property’ of water that is used by optical oceanographers to predict light propagation, image degradation, remote sensed ocean color, biological environment etc. in water.
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Product
Radiative Transfer Equation Solver
EcoLight-S
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EcoLight-S(ubroutine) is an extremely fast RTE (radiative transfer equation) solver developed for use as the optical component of coupled physical-biological-optical ocean ecosystem models, or as the radiative transfer forward-model core of implicit inverse models.
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Product
Submersible Laser-Diffraction based Particle Size Analyzer
LISST-200X
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The LISST-200X is Sequoia’s workhorse. It is a self-contained submersible laser-diffraction based particle size analyzer, designed for measuring suspended particle size and concentration in the aquatic environment – oceans, rivers, lakes, streams. A fast response temperature sensor and a high-resolution depth sensor makes it suitable for profiling or towing. With Sequoia’s optional BioBlock accessory it can be deployed for months on moorings or landers for long-term studies. For the system integrator, the LISST-200X can power and accept inputs from up to three external analog sensors. The LISST-200X is typically used for sediment, (harmful) algae, oil-spill, ocean optics, visibility, dredging, aquaculture, environmental and laboratory applications.
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Product
Multi-angle Polarized Light Scattering Measurements
LISST-VSF
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The LISST-VSF covers the angular range from 0.094 to 150°. Of this, the range 0.094 to 14.9° is covered with Sequoia’s 32-ring detector optics as in the LISST-200X. From 15 to 150° scattering from the length of a laser is viewed by a rotating eyeball. These data produce P12 and a noisy estimate of P22 (no P22 estimate at 45 and 135°).
