Development of an Inspection System for Micro Level Void Detection

In this paper we discussed a method to carry out a roughness inspection on the surface of fuel injection nozzle of ship engines. The nozzles are manufactured using hot isostatic pressing (HIP) technology. Microscopic blowholes are likely to be created during the process of manufacturing the nozzles, which causes the roughness on the surface even after fine machining. The objective of this research is to develop a technique to detect these microscopic blowholes. Digital image processing and a computational system are used to measure the roughness level. Length and breadth of the blowhole is measured using edge detection technique associated with a Gaussian filter and then edge drawing algorithm is used to draw fine edges along the detected edges. Based on the difference of intensity gradient along x-and y-direction, the edges of the blowholes are drawn. These detected edges are used to measure the size of blowhole.