Sequoia LISST-ABS Acoustic Sediment Sensor
Features
- Uses acoustic backscatter to measure the concentration of particles suspended in water
- Wide dynamic range of concentrations from 1mg/L to 30 g/L
- Plug-and-play interface with X-Series data loggers and telemetry systems
- Expedited repair and warranty service
- Lifetime technical support
- More
Overview
The Sequoia Scientific LISST-ABS is a single-point acoustic sediment sensor, designed to provide higher quality data than optical turbidity sensors. The LISST-ABS internally measures the Attenuation Corrected Backscatter (ACB). The ACB value is converted to an Uncalibrated Concentration (Cu) and then output. To convert the Uncalibrated Concentration to sediment concentration, a simple multiplier is required. The multiplier, or Cal Factor, is dependent on the specific type and size of sediment being measured. When a user recalibrates an instrument, this multiplier is updated.
Mechanics
The Sequoia Scientific LISST-ABS employs a high frequency of 8 MHz. Calibration of backscatter signal strength with sediment concentration remains nearly constant over a wide particle size range, ~40-500 microns. Over this size range, the Sequoia Scientific LISST-ABS calibration changes only about ~±30%. In contrast, over this same size range, optical turbidity sensors would change calibration by ~ ±600% over its mean value.
Remote Monitoring
The LISST-ABS sensor offers a plug-and-play interface to the NexSens X3 data loggers and telemetry systems. The X3 is available for pole-mount deployments with solar charging or connected to the SBP500 submersible alkaline battery pack for subsurface deployments.
- Frequency: 8 MHz
- Sample Volume: 10mm dia x 15mm L (located 5.5 cm in front of sensor)
- Resolution: 0.5 % of reading
- Range: 1 mg/L to 30 g/L (7 micron dust) or <20 g/L (200 micron sand)
- Calibration: Recommended with sediment samples
- Sensor Diameter: 2.00 in (5.08cm)
- Length: 13.25 in (33.65cm)
- Weight: 1 lb. (0.5Kg) in air; 0.5 lb. (0.22Kg) buoyant in water
- Transducer: 8mm dia, ceramic
- Power Supply: 9 to 18 VDC, 100 mA
- Maximum Depth: 100m
- Material: ABS Plastic
- Connector Type: Impulse MCBH-8-MP-SS
- Power on LED: Green, blink on update
- Sample Update Rate: 1Hz (average of 1000 measurements)
In The News
Climate Change and Microplastics: Monitoring Lake Champlain
Most people go to Lake Champlain for its exceptional views and thrilling boating, but it’s also home to a wide variety of interesting aquatic research projects. From studying microplastics to thermal dynamics of the lake, Timothy Mihuc, director of the Lake Champlain Research Institute (LCRI) at the State University of New York at Plattsburgh (SUNY Plattsburgh), has spent his career studying aquatic ecosystems. 
 
 As an aquatic biologist, he’s the main investigator on Lake Champlain’s research studies while also managing their grants, employees, and their hands-on buoy work. 
 
 Over the years, LCRI has received a number of environmental grants that aid in its monitoring research.
Read MoreCurrent Monitoring after the Francis Scott Key Bridge Collapse
On March 26th, according to The Baltimore Sun , a 984-foot, 112,000-ton Dali lost propulsion and collided with a support column of the Francis Scott Key Bridge, collapsing the structure. Soon after the event, search and rescue, salvage crews, and other emergency responders were mobilized after the collision. 
 
As salvage efforts progressed in early April, NOAA’s Center for Operational Oceanographic Products and Services (CO-OPS) responded to a request for real-time tidal currents data and deployed a current monitoring buoy—CURBY (Currents Real-time BuoY)—into the Patapsco River north of the Francis Scott Key Bridge.
Read MoreSoundscapes of the Solar Eclipse: Citizen Science Supporting National Research
On April 8, 2024, millions of people around the world had their eyes glued to the sky to witness a historic cosmic event. The total solar eclipse captured the headlines and the minds of many who became eager to gaze at the heavens as the sky went dark for a few minutes. However, not everyone used their sense of sight during the eclipse, some were listening to the sounds of the natural world around them as the light faded from above. 
 
 The Eclipse Soundscape Project is a NASA-funded citizen science project that focuses on studying how the annular solar eclipse on October 14, 2023, and the April 8, 2024 total solar eclipse impacted life on Earth. 
 
 The project revisits an initiative from the 1930s that showed animals and insects are affected by solar eclipses.
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