Sequoia LISST-Tau Transmissometer
LISST-Tau is a high-precision transmissometer for underwater vehicles, profiling packages, CTDs, and remote monitoring systems.
Features
- Measures optical transmission and beam attenuation
- RS-232 and analog real-time outputs
- Integrated temperature compensation & ambient light rejection
Your Price
Call
Stock
Check
Availability
Fondriest Exclusives
- Expedited repair and warranty service
- Lifetime technical support
- More
Overview
LISST-Tau is a high-precision transmissometer for underwater vehicles, profiling packages, CTDs, and other systems. With high-quality optics and a carefully selected LED source, it transmits a collimated beam through the water, and precisely measures the light transmitted through its 15 cm path. Light modulation with synchronous detection rejects ambient light, while oversampling and averaging yield better than 16-bit resolution. LISST-Tau’s digital controller applies calibration coefficients, corrects for temperature effects, and transmits data from both digital and analog outputs. Included software provides real-time display of data, and functions for checking and updating pure-water calibrations. An optional flow-through chamber simplifies calibrations and experiments. LISST-Tau advances the state of the art for in-situ transmissometers.
Remote Monitoring
The LISST-Tau transmissometer offers a plug-and-play interface to the NexSens X3 data loggers and telemetry systems. The X3 is available for pole-mount/buoy-based deployments with solar charging or connected to the X3-SUB submersible data logger with alkaline battery pack for subsurface deployments.
Parameters Measured
- Optical transmission
- Beam attenuation
Operating Ranges and Stability
- Operational temperature range: -3 °C to 40 °C
- Storage temperature range: -20 °C to 60 °C
- Beam attenuation range: ~0 m-1 to 30 m-1
- Linearity (concentration): >99 %
- Short-term stability (typical standard deviation over 1 minute)
- Transmission: 0.003 %FS (Green) / 0.005% (Red)
- Beam attenuation: 0.0002 m-1 (Green) / 0.0004 m-1 (Red)
- Long-term stability (6 hr test)
- Transmission: ~0.003 %FS/hr
- Beam attenuation: ~0.0002 m-1∙hr-1
Technology
- Optical path length: 15 cm
- Source wavelength: ~532 nm (Green) or ~650 nm (Red) LED
- Source spectral bandwidth: <10 nm FWHM
- Acceptance angle (half angle, in water): 1.0 °
- Optical transmission @ 16-bit resolution
Mechanical and Electrical
- Dimensions [Ø x L]: 5.1 cm x 40.6 cm (2.00″ x 16″)
- Weight [air / seawater]: 1.140 kg / 0.585 kg (2.5 lbs / 1.3 lbs)
- Depth rating: 2,000 m
- Sampling rate: 1 Hz
- External power input: 7 VDC to 25 VDC
- Current drain @ 12V: 42 mA average during sampling
- Connector: SubConn MCBH6M
- LISST-Tau transmissometer
- LISST-Tau 2-meter integrated communication and external power USB cable
- Windows software for real-time display of data, and functions for checking and updating pure-water calibrations
- Shipping case
Questions & Answers
Select Options
Products
0 Item Selected
Image
Part #
Description
Price
Stock
Quantity
SEQ-FP-LTAU-532NM
LISST-Tau high-precision transmissometer, 532 nm (green) LED source
Request Quote
Check Availability
SEQ-FP-LTAU-650NM
LISST-Tau high-precision transmissometer, 650 nm (red) LED source
Request Quote
Check Availability
Accessories
0 Item Selected
Notice: At least 1 product is not available to purchase online
Related Products
In The News
Monitoring OAE Efforts in Halifax: Fighting Climate Change with Emerging mCDR Strategies
Marine carbon dioxide (CO 2 ) removal (mCDR) is an emerging strategy that aims to fight climate change by taking advantage of the carbon capture potential of our oceans. There are multiple types of mCDR approaches being evaluated globally, one of which is ocean alkalinity enhancement (OAE). According to NOAA , OAE aims to increase the pH of water by either adding alkaline material to ocean surface waters or by removing acid from seawater. Due to the change in acidity, the chemistry of seawater changes, making it capable of absorbing greater volumes of CO 2 .
Testing CO2 Removal Strategies in the Pacific Northwest
The ocean plays a key role in carbon dioxide (CO2) removal and storage, also known as carbon sequestration. However, with increasing emissions, a large amount of CO2 escapes into the atmosphere, worsening climate change and leading to increases in surface temperatures. In order to mitigate some of these impacts, researchers like Ally Savoie at the Pacific Northwest National Laboratory (PNNL) are working hard to identify ways to safely improve the CO2 removal and storage capabilities in the ocean. Savoie started her career at Wright State University , where she worked in Silvia Newell’s lab examining biogeochemical cycling of nutrients in a river system. From there, she decided to pursue a master’s in marine science at the University of Southern Mississippi with Dr.
Smart Buoys Advance Climate Monitoring in Swiss Lakes
Lakes are sentinels of climate change . Globally, they are warming at an unprecedented but uneven rate, and in many places they also face direct human pressure, including from agriculture and recreation. In the Alps, scientists generally agree that climate change is of particular threat to remote lakes , where more pronounced warming threatens fragile ecosystems. Alpine Lakes in a Changing Climate Matteo Tonellotto is part of the team at the Environmental Observatory of the Italian-speaking region of Switzerland (OASI)–a multidisciplinary team of scientists, IT specialists, and chemical laboratory technicians committed to collecting, managing, and integrating high-quality environmental data.
Connecting with Nature in Real-Time at the Abernathy Field Station
Just five miles away from Washington and Jefferson (W&J) College is the 57-acre Abernathy Field Station . Generously donated by the Abernathy family in 2017, the field station has served as an outdoor lab to hundreds of undergraduate students over the years. Many classes use the Abernathy Field Station every week. For example, in BIO 111, students spend 15 weeks conducting their own research at the field station using a combination of sampling, field observations, and real-time environmental data, giving them a look into the world of science and a closer relationship with nature. “We like to start the students in the research process in their first Biology class.
