Conductivity, Temperature and Depth monitor
The conductivity, temperature and depth instrument helps scientists study ocean chemistry; it is the prime instrument for studying the ocean's chemistry in t he California Current.
A deep-sea monitoring instrument tethered to a steel cable, it descends into the ocean, relaying changes in temperature, salinity, water density and oxygen, and chemicals at varying depths.
At every station, it descends nearly 1,700 feet. Electronic instruments within it record temperature, conductivity, density, oxygen and concentrations of chlorophyll. Changes in electrical conductivity correlate with changes in salinity, while chlorophyll concentrations give clues about the abundance of phytoplankton.
The device is plunged into the ocean and scientists trigger the lid of each bottle to snap shut at various depths. Technicians and scientists collect the water samples for later examination.