Can someone who is familiar with the procedure of calibrating a Babolat RDC please provide a brief explanation? I'm curious as to the various springs used to calculate the stiffness measurements of racquets, how the process works, and if the spring rate of these calibration springs is known. And the same for the calibration of the swingweight measurement. Does it use the same springs or is there a different set? And if the spring rate is not known, can you provide some basic measurements, such as the diameter of the spring, the gauge of the wire, and the number of turns per inch? Thanks.