Electromagnetic method and procedures of nondestructive inspection of the corrosion protection of underground pipelines.

A triune mathematical model of an electromagnetic field is proposed, and procedures of fast noncontact inspection of underground pipelines are proposed. Methods and devices are developed for the determination of the distribution of cathodic protection current and the transition resistances of protective coatings in different sections of underground pipelines. The technology of integral, differential, and local inspections of main pipelines is described. [ABSTRACT FROM AUTHOR]