Inspection and Diagnosis Technology for Transmission Towers

Most transmission towers are constructed of galvanized steel for corrosion protection. After corrosion of galvanized steel progresses over time, the surface is repaired by painting. Once transmission towers are painted, they are repainted after a certain period due to paint deterioration. To give the order of priority to inspections and repairs, it is necessary to evaluate corrosion and paint deterioration, and to appropriately determine when to apply the first paint and when to repaint. In this article, the inspection and diagnosis technologies for transmission towers are introduced. In addition, the problems with evaluation methods of corrosion and paint deterioration through inspection and diagnosis are explained. For example, visual inspection of the painted surface is influenced by the subjectivity of the inspector, which may lead to variation in judgment. Considering these problems, improved evaluation methods have been developed. The paint deterioration evaluation methods using impedance measurement that can be used on-site for transmission towers as a quantitative method are also introduced in this article.