|
|
 |
| Suspended Sediment Sensors |
|
LISST family of instruments
LISST-StreamSide
LISST-SL
LISST-25X
LISST-100X
LISST-Portable
LISST-ST
|
|
Sequoia is the sole manufacturer of the LISST series laser
sediment/particle/bubble/droplet sensing instruments. Some of these instruments
deliver the optical volume scattering function
(VSF) of interest to optical oceanographers.
The LISST series includes submersible and non-submersible instruments. All
employ the small-angle forward scattering principle, also called low-angle laser
scattering or laser diffraction.
Submersible Suspended Sediment Sensors:
The submersible series includes:
- LISST-100X
- LISST-FLOC
- LISST-Deep
- LISST-ST
- LISST-25X
- LISST-SL
Of these, the LISST-100X is our workhorse. It delivers the
size distribution of suspended sediments in 32 logarithmically spaced size
classes. Different models of this instrument cover different rnage of sizes.
The LISST-FLOC covers the largest sizes,
7.5 to 1500 microns (nominal), and is intended for measuring flocculated marine
particles. These instruments can be used as laboratory instruments, with
provided accessories. The LISST-Portable (see below) is a portable version which can be
driven to a site (river, stream, highway runoff..) or carried on an airplane.
LISST-Deep is a deep version capable of
operations to 6000m.
The LISST-ST
is an extended version of the LISST-100X, with an added Settling Tube (ST stands
for Settling Tube). This instrument is designed to perform submerged settling
experiments to obtain settling velocities of 8 size classes. With the settling
column removed, the LISST-ST may be used as a -100X, but with less than optimal
flow through the sample volume.
The LISST-25X is a patented derivative product. It
delivers the suspended sediment concentration and mean size in two size classes
(2.5-63 and 63-500 microns).
All of the above submersible instruments
incorporate a depth sensor. They are powered by internal batteries and store
data internally.
The LISST-SL is
an isokinetic version of the LISST-100X developed for river sediment monitoring.
It senses river velocity and adjusts intake velocity to match. Optics and
electronics are enclosed. Data are stored on a bridge-top Topside box.
Field and Portable Particle/Sediment Size Analyzers:
- The LISST-Portable
- LISST-Streamside
- LISST-Infinite
The LISST- Portable is a field or laboratory device for particle size and
concentration measurements. It is also battery operated, easily
transported (car, airplane), and autonomous. Data are stored on
board. The LISST-StreamSide is meant for use in shallow streams or
rivers. The instrument is designed for placement in a shed. A
submersible pump is placed in the stream for delivering water to the
instrument.
The LISST-Infinite is designed for measuring very high concentrations
of sediment, such as occur in rivers. The instrument is placed in a
shed and again, water is pumped through it. A clean water source is
required for dilution. The instrument performas dilutions if needed.
For more information on these instruments, please click on the links at top of this page, or contact us.
|
|
|
|
|  | | LISST-Portable re-design |  | | Sequoia's LISST-Portable is undergoing a re-design in order to be equipped with a touch panel display similar to the one on the LISST-StreamSide. Also, all dataprocessing will now take place on-board in real-time so no data post-processing is necessary. The first units will ship in October 2008. | |  | |  | | | |
|