In this video, D-2 Inc. demonstrates a simple vessel-based deployment of its CTD using onboard memory, automatic logging, and a dedicated battery pack, allowing profiles to be collected without a real-time power or data connection to the vessel.
With the CTD set to automatic logging mode, data acquisition begins as soon as power is switched on and continues until the unit is turned off.
The D-2 CTD provides 128 MB of internal memory and records raw counts for pressure, temperature, pressure-temperature, and conductivity, together with time and date stamps. Its flow-through closed-field conductivity technology is insensitive to nearby structures and mounting geometry, allowing the instrument to be attached to an autonomous vehicle, profiling frame, or simple rope without compromising its factory calibration.
The instrument can be lowered from a small boat or larger vessel using a rope, cable, or similar tether, with data stored internally throughout the cast. After recovery, stored records can be transferred to a laptop or desktop using the OC-CTD-Test-Cable supplied with every instrument. Switching the CTD off and back on starts automatic logging again in a new file, allowing another cast to be recorded.
