The key points from this module are as follows:
It is not practical to stop complete corrosion of buried structures, so some criteria have been developed to ensure adequate protection. Each criterion has its merits and limitation. The Instant-off-potential criteria are widely used, though 100 mV criteria are more accurate.
The importance of coating buried structures are as follows;
It significantly reduces the current requirements for cathodic protection.
It reduces current attenuation.
Surveys of buried engineering structures are widely used as;
Diagnostics tools to assess corrosion of buried structures.
Effective installation of cathodic protection systems.
To locate coating defects and their conditions.
To check the performance of anodes.
To check hot spots and cost-effective cathodic protection.