In order to apply the electro-magnetic radar method as an inspection method for cover depth, this study proposed a method to set relative permittivity.
One is to correct the permittivity based on the relationship between the water content on the concrete surface and the relative permittivity, and the other is to measure the cover depth by correcting the permittivity based on the relationship between the water content on the concrete surface and the electromagnetic wave speed. As a result, it was confirmed that the accuracy was equal to or better than that of the electromagnetic induction method.
