Instrument installation and maintenance
Sea Bird (SBE) Thermo-salinometers are the most commonly used devices for measuring sea-surface salinity on board ships underway. These devices sample the water pumped in through a seawater intake and measure simultaneously the conductivity and the temperature to deduce salinity. The nominal instrumental accuracy of the measurement is largely sufficient to capture the surface variability. However, siting of the instrument, stability of the electronics, sufficient flow through the conductivity cell, air bubbles and contamination by fouling and deposits may dramatically increase the measurement errors and even lead to discard the data.
In order to obtain the best quality for the real time measurement
- TSG should be installed in such a way that the flow on the conductivity cell follows the manufacturer recommendations and air bubbles are avoided
- The sensors must be calibrated annually
- The TSG must be cleaned regularly to prevent fouling
- We recommend installing flowmeters on the ships to get a direct information on the flow.