Once the stylus' effective diameters are established and the relative position to the machine is known, a special analysis program takes that information to determine any unknown diameters of the ball stylus. The CMM data processor will store all midpoint coordinates as reference coordinates. Remaining styli to be calibrated are generated through differences with the first one, then they too are stored. When using styli of different lengths, diameters, etc. on the same adapter plate to measure the same area, this system makes it so they appear to have been taken with just one stylus. This means that no matter what stylus you use to measure a point, you will always receive the same result.