We notice that the polynomial interpolation of order 1 (a line) is
a better approximation for these data; its equation is in form ߟௗ = 0.9986ߟ + 0.0003this line slopes is almost
equal to 1 (0.9986) and the coefficient 0.0003 very near to zero thus we can neglect it, and consequently we can
make the following approximationߟௗ = ߟ. Starting from the preceding analysis we can consider that the values
obtained by the model are very close to the values of the measured efficiency output and by consequence the model
is valid