Title :
Progress report on the ENDECO free-fall CTD [conductivity-temperature-depth sensor system]
Author :
Brainard, Edward C., II
Author_Institution :
Endeco Inc., Marion, MA, USA
fDate :
7/1/1988 12:00:00 AM
Abstract :
A description is given of a vehicle system designed to meet the World Ocean Circulation Experiment (WOCE) specifications and provide a low-cost alternative for the oceanographer to using ships with hydrographic winches and dedicated conductivity-temperature-depth (CTD) systems. The vehicle is tracked using a pressure-coded acoustic pinger synchronized to an IBM-compatible computer aboard the deployment vessel. With horizontal range derived from these measurements, the vessel can maneuver to the pickup site. The system uses a temperature and conductivity sensor designed to allow at-sea calibrations in the triple point of water and gallium standard temperature cells. Water samples are obtained using 12 evacuated pyrex glass 250-ml sample bottles with special break-off fill caps. The round-trip travel time for the free-fall CTD is approximately 1 h to 6500 m compared to 4 h using conventional techniques
Keywords :
computerised instrumentation; electric sensing devices; electrical conductivity measurement; measurement standards; microcomputer applications; oceanographic equipment; temperature measurement; 1 hour; 6500 m; Ga melt point standard; IBM-compatible computer; World Ocean Circulation Experiment; at-sea calibrations; conductivity sensor; conductivity temperature depth system; free fall system; pressure-coded acoustic pinger; temperature cells; temperature sensor; triple point of water; Acoustic measurements; Acoustic sensors; Calibration; Conductivity; Marine vehicles; Ocean temperature; Sea measurements; Sensor systems; Temperature sensors; Winches;
Journal_Title :
Oceanic Engineering, IEEE Journal of
