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 X2, X2-SDL, and X2-CB data loggers and telemetry systems
- Expedited repair and warranty service
- Lifetime technical support
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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 full line of NexSens X2 data loggers and telemetry systems. The X2 is available for pole-mount deployments with solar charging near streams and rivers; the X2-SDL includes an integrated 16 D-cell alkaline battery pack for subsurface deployments; and the X2-CB is designed for integration on CB-Series data buoy platforms.
- 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)
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