Laser Diffraction Particle Size Analyzer (PSA)

Beckman-Coulter LS100Q PSA

This instrument uses laser diffraction to record a particle size spectra fora given sample. It has a range of 0.4-1000 microns.

Laser In-Situ Scattering Transmissometer

Sequoia LISST-100

This is a submersible optical instrument that measures particle concentration and particle size spectra, as well as pressure and temperature. This instrument records small-angle distribution of light scattered from suspended particles. Then, using laser diffraction theory, this data is used to calculate particle concentration and particle size specta.

2. CTD unit

This instrument measures conductivity, temperature, and depth (CTD). Furthermore, salinity can be derived from conductivity and temperature data.

3. Digiquartz Pressure Instrumentation (Parascientific, Inc.)

This instrument takes pressure readings based on the physical deformation of strain gages in the instrument. This deformation is translated into an electrical signal and recorded as data.

Acoustic Current Meter

Nortek Aquadopp

In contrast to the SonTek ADV, this profiler records 3-axis velocities and a range of water depths, rather than a fixed point. This instrument emits acoustic signals, and then determines velocity based on the backscatter from suspended particles. This instrument also records pressure, temperature, tilt and compass readings.