In a world’s first, Sequoia Scientific, Inc. of Bellevue, WA, USA has invented a method (patent pending) to pair data from an optical turbidity meter (e.g. an OBS) with Sequoia’s acoustic backscatter sensor, the LISST-ABS. The pairing of the acoustic and the optical data leads to a much-improved estimate of the suspended sediment concentration (SSC), compared to the estimate that either sensor can provide on its own. The key advantage is that calibration is not affected by changes in grain size. The new methodology allows for measurements of SSC that is within a factor of 2 of the actual value, e.g. based on sampling and subsequent filtration. This is an order of magnitude improvement over existing technologies.
Sequoia is also introducing a new instrument package based on this technology, the LISST-AOBS Super-Turbidity meter. All existing LISST-ABS sensors can be expanded to the LISST-AOBS Super-Turbidity meter. Also, all existing turbidity sensors can be expanded to the LISST-AOBS Super-Turbidity meter – contact Sequoia for details!
The implications of the new method and the introduction of the LISST-AOBS Super-Turbidity meter are two-fold:
- existing regulations (e.g. for stormwater, construction, environmental monitoring) that calls for monitoring of turbidity can be adhered to while
- the user AT THE SAME TIME can obtain an ACCURATE estimate of SSC.
According to the US EPA, excessive sediment is the leading cause of impairment of the Nation’s waters. High SSC values influence virtually all aspects of aquatic life in a detrimental manner. Accurate measurements of SSC with low-cost sensors that can be deployed for months or years are therefore of importance for a wide range of environmental quality programs, remediation efforts, court cases etc.
Sequoia’s LISST-AOBS Super-Turbidity meter can help provide the data needed to make the decisions that will protect the Nation’s waters.