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
Combating Water Insecurity in Saskatchewan with Real-Time Data
The prairies of Saskatchewan can be described as one of the least water-secure parts of Canada, making water quality monitoring essential for informed resource management in a region already facing water insecurity. While natural physical properties worsen some of the poor water quality conditions in the region, others are connected to land use. 
 
Having grown up spending summers on the shores of Lake Huron, Helen Baulch, an associate professor at the School of Environment and Sustainability at the University of Saskatchewan , has always been dedicated to the protection of water resources. 
 
Looking back fondly at her childhood playing along the shore, Baulch also recalls the invasion of quagga mussels during her teenage years and watching the lake change as a result.
Read MoreSeametrics Turbo Turbidity Logger: Boost your Turbidity Monitoring
The Seametrics Turbo Turbidity Logger is a self-cleaning turbidity sensor capable of internally logging over 260,000 data records. The sensor enables researchers, compliance officers, and contractors to monitor turbidity in various applications, from construction and dredging sites to wastewater effluent. 
 
 Due to its narrow width, this device can be deployed in a range of areas, from small well spaces to rivers and streams. The stainless steel housing and built-in wiper allow the sensor to withstand long-term deployments and reduce the need for maintenance trips. 
 
 The logger accurately records temperature and turbidity up to a depth of 50 meters.
Read MoreCollecting Data at the Top of the World: How Scientists Retrieve Glacial Ice Cores
A helicopter touches down in the small town of Sicuani, Peru, at an elevation of 11,644 feet. Earlier that day, a boxcar brought fuel, drills, food, and other equipment for a glacial expedition. The year is 1979, and glaciologist Lonnie Thompson is preparing to lead a team to the Quelccaya ice cap in hopes of becoming the first scientists to drill an ice core sample from this glacier. 
 
 The only problem? The glacier is located at 19,000 feet in one of the most remote areas of the world. The helicopter takes off from the town, but the thin atmosphere at that elevation does not allow it to safely touch down on the ice– due to the aircraft’s weight, and it becomes unstable when the air is less dense.
Read More