Sequoia Scientific

Sequoia Newsletter October 2016



Welcome to Sequoia Scientific’s October 2016 Newsletter. Some of you are probably  familiar with who we are.  For those who are not, We Measure Particles.  We manufacture and sell field and portable instrumentation for measuring particle size distribution and concentration, and light scattering properties of marine particles. Below is some newsworthy information we thought you would be interested in.

Sequoia Scientist receives International Award

mobley_photo_lowresSequoia is thrilled to announce that Dr. Curtis Mobley, our Vice President for Science since 1996, has been named the winner of the 2016 Jerlov Award for his lifetime of contributions to optical oceanography and ocean-color remote sensing.  This internationally recognized award is given every two years in recognition of an individual’s research, education, or service contributions that significantly advance our knowledge of how light interacts with the oceans.  Dr. Mobley’s papers and books have been cited over 9,000 times, and his HydroLight software is the industry standard for computations of underwater light fields.  He will receive the award on October 27 at the Ocean Optics XXIII Conference in Victoria, Canada.  For further information and his award citation, see

200x_opticsend-squareLISST-200X eliminates old clumsiness of LISST-100X

The LISST-200X is a new version of our popular LISST-100X submersible particle size analyzer.  By creating a brand new instrument, we were able to take the best of the LISST-100X and improve upon it.  The LISST-200X is smaller, has a wider size range (1.00 to 500 microns) and can go to deeper depths (600m). (Comparison Chart)  However, the biggest improvements are less obvious.  We have significantly streamlined the processing of the data by storing all the information needed for processing the data in one file.  The LISST-200X can also output Mean Size and Total Concentration as an analog voltage which allows it to be connected to a CTD or other datalogger to get real time information while storing the data for detailed size distribution in internal memory.   For more information on the new features read our “Why the LISST-200X is smarter not just smaller” article.

Software version 5.1 for LISST-100X self-diagnoses backgrounds.

Background QC FailFor all those users of our LISST-100X series instruments who have asked, after collecting a background file: Is my background good?, there is help.  The recently released Version 5.1 of the LISST-SOP software grabs a background file, as before, and then – and this is new – evaluates it, i.e. it checks if laser output is within spec, if optics are in alignment, if windows are clean, if the water you used was clean, and if scintillation due to temperature microstructure in the cell contaminated the background data. The software then makes suggestions on whether to accept the file, or collect a new file for specified reasons and with specified cures, e.g. clean the windows, or use cleaner water. In this way, this release helps you to acquire the best possible background file.  Visit the Software and Download section of the LISST-100X webpage to download LISST-SOP Version 5.1.

LISST-ABS – Gaining Acceptance

The LISST-ABS, our acoustic backscatter sediment sensor, continues to gain acceptance by customers.  They have had many successful deployments in multiple types of applications and have done extensive lab testing.  Learn more….

A LISST for gliders is in development

LISST-GliderSequoia has just received a contract from the US Navy via Rutgers University for the development of a version of the LISST-200X that will fit into a Teledyne Webb Research Slocum G2 Glider.  The contract includes the delivery of 10 instruments to Rutgers University.  Sequoia will be working with Webb Research to make this version of the LISST-200X, which we are currently calling LISST-Glider available for other new and existing Glider customers.  This particular application is to measure suspended sediments during typhoons. The LISST-Glider also has many other applications such a tracking harmful algae blooms, dredge monitoring or oil spill plumes. (Read Announcement)

LISST-VSF  – our NASA funded volume scattering instrument finds popularity

The LISST-VSF is a very specialized instrument that measures laser light scattering from 0.1 to 150 degrees.  It was developed with SBIR funding from NASA.   Recently published papers on using the LISST-VSF has contributed to a sudden burst of orders from the USA, Germany and India and orders developing in China.     (Learn More)

Sequoia Presents New Idea on Turbine Abrasion Protection

Turbine_abrasion1Sequoia’s LISST-Infinite and LISST-Hydro products generate data on sediment concentrations in water entering turbines. However, there has been no guidance for plan operators on what levels are dangerous, or at what level the operator should shut down turbines. At a conference of the IAHR in Grenoble, France, 4-8 July 2016, Sequoia president Yogi Agrawal proposed a simple idea. According to this idea, a cost of abrasion is calculated at any instant. This quantity is the cost of repair of a turbine multiplied by the ratio of current sand transport rate (tons/hr) divided by the total sand transport after which repair is necessary. The shutdown is recommended when this cost exceeds revenue generation. The same idea was proposed simultaneously by Prof. Robert Boes of Switzerland.  Read Abstract and Full Paper…

Upcoming Conferences and Meetings

Sequoia will be exhibiting at the Ocean Optics meeting in Victoria, BC on Oct 24-28, 2016.  We will have many instruments on display including the LISST-VSF.
Sequoia will also be exhibiting at the 2016 AGU Fall Meeting in San Francisco, CA on Dec 12-16, 2016.  Stop by booth 444 to see the latest instruments including the LISST-200X.

Share your success and News

Do you have a success story or news that you would like to share with others interested in Sequoia products?  Some great photographs of LISST instruments in the field or a picture of a Giant Sequoia seedling you received from us?  Please send it our way.  We would love to hear from you. Please send an email to