 At high partial pressure in the adsorption/desorption the Kelvin equation gives the pore size distribution of the sample.In mercury porosimetry, the mercury is forced into the aerogel porous system to determine the pores' size, but this method is highly inefficient since the solid frame of aerogel will collapse from the high compressive force.The scattering method involves the angle-dependent deflection of radiation within the aerogel sample.