| 摘要 |
<p>Provided is a non-destructive diagnosis method for diagnosing occurrence of an oxide film on a metal material, particularly a metal wire and/or a metal cable, covered with a polymer composition, the cover having a predetermined thickness E, using a non-destructive diagnosis device. The non-destructive diagnosis device includes an optical system that includes: an oscillation section that oscillates an electromagnetic beam having a predetermined polarization direction and having a predetermined frequency in a sub-terahertz band; and a detection section that detects an electromagnetic beam having a predetermined frequency in a sub-terahertz band, wherein the oscillation section includes an electronic device as a light source for oscillating an electromagnetic beam, and the predetermined frequency in the sub-terahertz band is a frequency of 0.05 to 0.2 THz. The non-destructive diagnosis method includes the steps of: providing a covered metal material that is a diagnosis object; arranging the metal material with respect to the oscillation section in such a manner that the predetermined polarizing direction is directed in the same direction as that in which the metal material extends; projecting an electromagnetic beam from the oscillation section to the covered metal material; detecting a reflection intensity of an electromagnetic beam reflected by the covered metal material with the detection section; and comparing the reflection intensity of the electromagnetic beam from the metal material as the diagnosis object, which has been detected by the detecting step, with a reflection intensity of the electromagnetic beam reflected from a metal material covered with a polymer composition that serves as a reference, the cover having the same thickness E as that of the metal material as the diagnosis object, in which an amount of an oxide film of the metal material is less than a critical amount.</p> |
