Dimensional Metrology by Digital image Processing using Labview

Ring gauges are measured using vernier caliper, inside micrometer, precision coordinate measuring machine, length measuring machine (horizontal metroscope) in order of accuracy required and quality of the ring gauge. The accuracy obtained with these devices varies between 0.020 mm and 0.0005 mm. However, all these instruments/ devices are traceable to the length standards through gauge blocks. The necessity for such a method is mainly due to modern production technology which is taken more and more art to the hands of specialized metrologists. The latter asks for a high degree of confidence in the availability of the measuring instruments, which for economic reasons often have to work near their performance limits. An attempt has been made to measure the precision ring gauges directly by image processing technique with conic kernels and their orientation, which gives a more accurate non contact apparatus. This paper presents a general framework for analyzing structural asymmetry of ring gauge