Design of straightness tester for deep pipe

Based on the principle and technology of laser and optoelectronic inspection, an optoelectronic measuring method is presented to measure straightness of the deep pipe with a diameter of 35mm by using the quadrant detection, precision machine, image processing and computer technology for reference. The overall structure of system is discussed, and the measuring principle of the system is analyzed. Then, the corresponding formula to calculate the straightness of the deep pipe. The system is used to measure a deep pipe with the length of 1.15m and inner diameter of 35mm. Finally, the straightness curve of whole deep pipe is given by data fitting. The results show that the system resolving power can reach 0.01mm, which indicates that the measuring method is applicable.