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Sequoia Scientific

LISST-RTSSV

Real-Time Size and Settling Velocity Instrument

The LISST-RTSSV measures in-situ particle size, settling velocity, and concentration.

See a list of papers published with LISST-RTSSV data here!

The LISST-RTSSV uses two cameras with differing magnification to image particles ranging from 3.6 microns to 4,200 microns. In-situ particle setting velocity is measured using a built-in settling column that can be sealed off from the environment. Particles and water are drawn into the chamber and allowed to settle past the cameras. Particles are counted, sized, and tracked via image processing software.

Originally developed for studying sediment plumes related to deep-sea mining operations, the LISST-RTSSV has broad applicability in other industries such as environmental monitoring, dredging, and sediment research where understanding the transport and fate of particles is critical.

The LISST-RTSSV is actively quoting as of Q4, 2024 and we do take orders. Production units will start shipping in Q4, 2025 for orders received in Q1, 2025.

Features

• Dual high-resolution particle cameras
• Vertical settling velocity column
• 6,000 meter depth rating
• Pump operated settling column door designed for deep sea use
• Software included with instrument
• Accessory cable lengths available as desired
• Externally powered
• Internal data logging
• Instrument ships in rugged case

Specifications

Parameters Measured
• Particle Size (3.6 µm to 4,200 µm)
• Volume Concentration
• Particle Setting Velocity (10 µm/s and 17,000 µm/s)

Technology
• Small Particle Camera (SPC) and Large Particle Camera (LPC) with overlapping fields of view
• Telecentric illumination

Mechanical and Electrical
• Dimensions [W x H x L]: 22.86 cm x 25.4 cm x 101.6 cm (9”
x 10” x 40”) including the clamps, pump and door assembly
• Weight [air / seawater]: 40.82 kg / 20.41 kg (90 lbs / 45 lbs)
• Depth rating: 6,000 m
• Material: black anodized aluminum w/sacrificial anode protection
• External power input: 12 VDC to 30 VDC
• Current drain: 1.3 A (max) @ 24 V
• Sampling Rate: 10 Image pairs per second
• Storage: 1.74 TB internal hard drive (approx. 100,000 image pairs)
• Connectors: SubConn MCBH5M, MCBH8M, DBH8M
• Temperature (operating): -3 °C to 40 °C
• Temperature (storage): -20 °C to 60 °C

Software & Downloads

  • LISST-RTSSV Datasheet
  • Accessories

    LISST-RTSSV Item # and Description

    Item #DescriptionThumbnail
    SEQ-FP-LRTSSVLISST-RTSSV - Real-Time Size and Settling Velocity instrument

    FAQ

    Does the LISST-RTSSV measure temperature and depth?

    No. The LISST-RTSSV is designed for integration and has no temperature or pressure sensor.

    Does the LISST-RTSSV have internal power?

    No. The LISST-RTSSV is designed for integration and does not have any internal power. Sequoia does not offer battery packs for the LISST-RTSSV.

    We recommend the Sea Battery Power Module from Deep-Sea Power and Light – that is the battery we at Sequoia use for our own LISST-RTSSV test deployments.

    Can I rent the LISST-RTSSV?

    No.

    Can a CTD power the LISST-RTSSV?

    It depends on the CTD: The RTSSV operates on 12 V with a current draw of around 2.6 A at 12 V. If the CTD can provide that it will be fine. Check with your CTD supplier or CTD data sheet.

    A Sea-Bird 911 CTD is 14.3 V with a maximum current of 1 A, so a 911 will not be able to power the LISST-RTSSV.

    Can we leave the settling door open and continuously slowly pump particles through the chamber as the CTD is descending and ascending?

    First, see above for power requirements. If the CTD can meet those, it is possible to remove the door and operate the other pump.

    On a CTD, what is the best way to figure out where the LISST-RTSSV is in the water column (given that it has no pressure sensor)?

    The images are time stamped, and they would have to be matched against the CTD data stream and time stamp afterwards.

    We want to integrate the LISST-RTSSV into a subsea observatory. Can we offload images while it is collecting data?

    Yes, when the instrument is connected to Ethernet, images can be offloaded, and the images can be accessed as a network drive.