3D system for the measurement of tube eccentricity: an improved, rugged, easy to calibrate layout

A rugged 3D optical system, easy to use and to calibrate, for the measurement of tube eccentricity has been developed in response to industrial demands for improved compactness and lower cost with respect to a previous layout developed in our laboratory. The system makes use of two optical laser projector–detector heads, and of suitably updated calibration and measurement procedures. This new layout shows a type A standard uncertainty of 0.03 mm over a tube diameter range from 10 to 60 mm and for tube thicknesses in the order of 3 mm. The new system can be easily built into a compact engineered version for applications in the industrial harsh environments of tube production. This system solves in a remarkable way the problem of measuring the eccentricity of a tube directly along the production line, without the need for machining it at the cut ends, and therefore reducing the amount of waste by means of the reduction in the time required to correct the process as a consequence of an eccentricity error. (paper)