Variation of the dimensionless sensitivity \(\eta\left(T\right)=\frac{d\ln R}{d\ \ln T}\) with temperature\(\)  \(T\), as described in Eq. \ref{eq:ChebyshevDerivative}. The values are calculated from the Chebyshev fit to Eq.\ref{eq:Chebyshev} for the original \(R\left(T\right)\) calibration data using the differentiation function built into the Chebyshev.fit method.