In the application of industrial endoscope, crack detection is one of its main applications. Because the probe diameter of the industrial endoscope is relatively small, it is easy to check the interior of the equipment through the slit or small hole, so that the tester can see the video image on the display, judge whether there are cracks, cracks and severity, and make correct replacement, maintenance or repair decisions. Compared with the disassembled detection equipment, industrial endoscope has the advantages of low cost and high efficiency. Now, JEET industrial endoscope is widely used in the detection of metal cracks.
Metal crack is an instability defect caused by the non cracking of some weak parts of the whole metal under stress. In the actual metal parts, all kinds of microcracks will inevitably appear, which will gradually produce and grow in the process, or in the use process, or under a certain load environment. When components expand to critical dimensions, they will be completely destroyed. That is, the fracture of metal materials can be divided into three stages: crack initiation, crack metastable propagation, unstable propagation and fracture, and the latter can lead to equipment failure or accident. The non-destructive inspection shows that the parts exceeding the critical size shall be discarded and replaced in time to avoid accidents or further economic losses. In the nondestructive testing of metal cracks, visual inspection is the main detection method, and industrial endoscope is commonly used.