Which of the following is NOT a tool to control corrosion?

Enhanced visibility is not a tool used to control corrosion. In the context of corrosion management, visibility refers to the ability to see or identify the corrosion-related issues, but it does not actively prevent or mitigate corrosion itself.

On the other hand, protective coatings, environmental alteration, and cathodic protection are all established methods for controlling corrosion. Protective coatings serve as a barrier between the metal and corrosive elements, preventing direct contact and subsequent corrosion. Environmental alteration focuses on modifying the environment around the material to reduce corrosion potential, such as controlling humidity or reducing exposure to corrosive agents. Cathodic protection is a technique that employs electrical methods to reduce the electrochemical activity responsible for corrosion, usually applied to underground and submerged structures.