High precision roundness measurement with two chromatic confocal sensors

As a fundamental geometric indicator, high precision roundness measurement is the basis evaluation index of cylindrical or spherical parts. In most roundness measurements, the rotation platforms are used to bring certain rotation error to the measurement result. Two-probe method is a typical roundness measurement strategy with error separation technique, coming from three-probe method with low cost, online integration, flexible installation, etc. We developed a roundness measurement system with three chromatic confocal displacement sensors with flexibility and high axial-resolution. As the measurement start, two sets of displacement data are achieved to take part in the frequency calculation. A typical cylindrical workpiece was measured for its roundness, which was very close with the measurement result by an ultra-precision roundness meter. In a word, the chromatic confocal roundness measurement system is feasible to provide high precision roundness with two-probe method.