Cathodic protection does not exist when the ohm reading is what?

Cathodic protection is a crucial technique used to prevent corrosion in pipelines and other metal structures. It works by supplying electrons to the metal surface, which inhibits oxidation and thus corrosion. When assessing the effectiveness of cathodic protection, various measurements can be taken, including ohm readings, which indicate the electrical resistance in the cathodic protection system.

If the ohm reading is infinite, it suggests that there is no electrical connection between the anode and cathode, which effectively means that no protective current can flow. This situation indicates that the cathodic protection does not exist, as the fundamental principle of cathodic protection relies on a conductive path that allows for the flow of electrons to the metal surface needing protection. In contrast, lower ohm readings (such as zero, one, or ten) indicate some level of connectivity and electron flow, which means that cathodic protection is functioning.

This is why an infinite ohm reading is indicative of a complete lack of cathodic protection.