The Laser as an Inspector

Scientists are putting laser beams to work as inspecting tools, in the Republic of China, as part of the government's big push to improve the quality of exported goods. The process is called "Holographic Non-destructive Testing (HNDT)." This new technique will be introduced for use by hardware manufacturers, tire manufacturers, electroplating factories and precision industries. The research work is being undertaken by the Tjing-ling Industrial Research Institute in cooperation with the Tjing-ling Industrial Development Foundation and National Taiwan University. Dr. Ching-piao Hu is in charge of the research project. HNDT's high sensitivity and accuracy are particularly useful in the inspection of material microcracks and mal-glued connections of tires, composite materials and honeycomb structures. At present, the Institute plans to use the available equipment to continue expanding such testing processes as checking the straightness and roundness of cylinders.

Surface contouring by moire sum to detect the surface geometry

Surface contouring by moire sum

Inspection of surface modification

Abrupt change of fringe shows the defect of the tire

Surface contouring of a machine part

Surface contouring by shadow moire