Detection of Double-layer Air Gap Defects Based on Terahertz Imaging Method

Composite insulators are prone to internal defects and the detection can be more difficult when the defects are overlap in the radial direction. A THz imaging system including THz spectrometer and sample scanning system was designed and set up to detect the defects. The flat sample with double-layer air gap defects of different shapes inside were made to simulate the composite post insulator. We c...