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The LISST-Deep instrument obtains in-situ measurements of particle sizedistribution, optical transmission, and the optical volume scattering function(VSF) at depths down to 3,000 meters. Using a red 670nm diode laser and a custom silicon detector, small-anglescattering from suspended particles is sensed at 32 specific log-spaced angleranges. This primary measurement ispost-processed to obtain sediment size distribution, volume concentration,optical transmission, and VSF. The LISST-Deep is programmed and operated like a LISST-100X .

The LISST-Deep is rated to a depth of3,000m and can be ordered as a type B (1.25-250µm) or type C (2.5-500µm) size range.
LISST-100X (click for larger image)		If you study the design of the LISST-Deep (see the picture), and compare it with the LISST-100X (shown to the left), it is clear that the mechanical design is very different from that of the LISST-100X. The optical path is more or less in the middle of the instrument, not at the end. This means that no accessories available for the LISST-100X will work with the LISST-Deep, with the exception of communication cables and instrument stands. No BioBlock, mixing chambers or path reduction modules are available for the LISST-Deep.

Also, because of the much thicker wall of the pressure housing, there is no room for internal battery packs as for the LISST-100X. The LISST-Deep must be powered externally at all times. This is typically achieved by connecting it to a CTD, getting power from the CTD. A cable for connecting to a CTD will be included, if the customer supplies Sequoia with the pin-out of the CTD upon ordering. Upon request, Sequoia can furnish a quote for a LISST-Deep external battery pack with cable for connecting to the LISST-Deep.