Strange–Rahman–Smith equation
The Strange–Rahman–Smith equation is used in the cryoporometry method of measuring porosity. NMR cryoporometry   is a recent technique for measuring total porosity and pore size distributions. NMRC is based on two equations: the Gibbs–Thomson equation, which maps the melting point depression to pore size, and the Strange–Rahman–Smith equation,  which maps the melted signal amplitude at a particular temperature to pore volume. Equation
If the pores of the porous material are filled with a liquid, then the incremental volume of the pores  with pore diameter between  and   may be obtained from the increase in melted liquid volume for an increase of temperature between  and  by:

Where:	  is the Gibbs–Thomson coefficient for the liquid in the pores. References

Equations of physics