“…The error in the estimation of the model is reduced if the number of measurement frequencies is increased [57], because the model that provides a best fit to all frequencies provides a safeguard against noise at any frequency. For this reason, a high number of frequencies has been used in the two studies carried out: 20 points used in the hardware validation study described in Section 3.1 and 50 for the software validation study described in Section 3.2 (all frequencies are in kHz): 5,6,7,8,9,10,11,12,13,14,15,16,18,20,23,25,28,31,35,39,43,50,54,60,67,75,83,93,100,115,128,143,159,177,200,220,245,273,304,339,378,421,469, 500, 582, 649, 723, 806, 898, 1000. The points that were only used in the hardware validation study are underlined.…”