Sequoia has launched the LISST-Tau, a compact 2,000m-rated high-precision transmissometer designed for unmanned underwater vehicles (UUVs) and systems such as ROVs (remotely operated vehicles) and towed platforms.
With high-quality optics and a choice of either green or red light source, it transmits a collimated beam of 15 cm pathlength through the water, and the detector precisely measures the amount of light received in order to measure the optical properties of the water. Light modulation with synchronous detection rejects ambient light, and oversampling and averaging provide a yield better than 16-bit resolution.
The 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.
Dr. Ole Mikkelsen, President of Sequoia, commented: “We are delighted that we are able to bring a high precision transmissometer to market. Our particle-sizing LISSTs, on the market since 1995, have always been able to measure transmission but the LISST-Tau is our first dedicated transmissometer. It has been field-tested and performs very well in challenging waters and at depth.”
