conductivity-temperature-depth (CTD)

oceanographic tool used to determine the essential physical properties of sea water: conductivity (salinity), temperature, and depth. Depth measurements are derived from measurement of hydrostatic pressure and salinity is measured from electrical conductivity. The CTD may be incorporated into an array of sampling bottles referred to as a carousel” or “”rosette””. The sampling bottles close at predefined depths

Synonyms:
triggered either manually or by a computer