Coefficient of Volume Change

The coefficient of volume change 1 ($//<![CDATA[ \begin{array}{l}m_v\end{array} //]]>$) in Coefficent_Volume_Change_1 is defined as:

$$//<![CDATA[ \begin{array}{l}\displaystyle m_v=\frac{1}{M}\end{array} //]]>$$

CPT in Geotechnical Practice p 71

Where:
     $//<![CDATA[ \begin{array}{l}M\end{array} //]]>$ the constrained modulus, and is taken from the Constrained_Modulus_1 field.