3D measuring industrial endoscopes can present a three - dimensional view of the distribution pattern of corrosion areas in pipelines (such as seamless steel pipes and FRP pipes) transporting acids, alkalis, organic solvents, etc. They can accurately measure the scaling thickness and range, measure the length and propagation angle of weld cracks, provide data support for anti - corrosion treatment or replacement of pipelines, and reduce the risk of medium leakage.