$//<![CDATA[ \begin{array}{l}\displaystyle \mu_{ob}(R_s) = A \cdot \left( \mu_{od} \right)^B\end{array} //]]>$,  $//<![CDATA[ \begin{array}{l}A = c_1 \cdot (R_s + c_2)^{c_3}\end{array} //]]>$, $//<![CDATA[ \begin{array}{l}B = c_4 \cdot (R_s + c_5)^{c_6}\end{array} //]]>$

$//<![CDATA[ \begin{array}{l}c_1 = 10.715, \ c_2 = 100, \ c_3 = -0.515, \ c_4 = 5.44, \ c_5 = 150 , \ c_6 = -0.338\end{array} //]]>$