How to measure the coaxiality of the workpiece with three-dimensional yuan, and what kind of method?

Measurement of coaxiality need to fit out two circles, three-dimensional measurement of the workpiece along the Z-axis direction of the two circles, that is, where the two circles are located in the Z-axis position were in the surface of the workpiece to hit the point of the fitted circle, you can use the 16-point, 32-point, 64-point, 128-point and other ways of fitting, in a word, the more points, the greater the precision of the results of the measurement, but the measurement will also be relatively slow. The distance between the centers of these two circles in the XY plane projection point is the coaxiality. In addition with the roundness meter is a professional measuring instrument to measure the coaxiality, compared with the three-dimensional, after clamping the workpiece, the roundness meter has the X-axis, Y-axis leveling function, and it does not have to hit the point like three-dimensional, the probe can be automatically rotated along the circumference of the workpiece surface to measure, so the measurement efficiency is high, and the accuracy is also high.