The present work was carried out with the objectives of supplying to CP designers data collected in
situ, in the actual environment in which the protected structure is deployed. Sensors arrays have been
deployed at six different sites from 35 m to 900 m depth. The measurements are based on the
deployment of a CPC sensor which records the coupling current between a cathode and an anode, and
the cathode potential.
The effect of temperature and pressure on calcareous deposit properties was put into evidence and
was useful to explain the different pseudo polarization curves.
For carbon steel: The results are broadly quite in a good agreement with standard and
recomendation.
For stainless steel: The initial current was independent of the location; the steady state current demand at -600 mV/Ag.AgCl depends strongly on the environment ; the current demands tent to decrease with
time in tropical and arctic zones, but increased in sub-tropical area and the current demand at -
950 mV/Ag.AgCl does not depend on the location.
Key words: Cathodic Protection; in situ data collection; deep sea; calcareous deposit; carbon steel;
Stainless steel