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Measuring the outer diameter of large workpieces with laser and CCD
The outer diameter of large workpieces (generally greater than 500mm), its high-precision measurement has always been a common problem that needs to be solved in China's machinery industry. Laser technology has been used in length measurement in terms of length measurement. In the production workshop environment, the relative measurement accuracy of the dual-frequency laser length measuring instrument can reach 10~(-7)mm or more. At present, the measurement requirements proposed by the steam turbine industry are: measuring range 1~4.2m, measuring accuracy ±3×10~5D (D is the measured diameter), it can be seen that laser technology can fully meet the accuracy factor of length measurement in large diameter measurement. The key is how to accurately capture the two measurement points on the diameter, that is, accurately positioned, thereby converting the diameter measurement into a simple length measurement. This paper proposes a large workpiece outer diameter from the perspective of practicality.