This method is for determining the pore size distribution and pore area of materials by mercury intrusion. Total port volume (intrusion volume), total pore area, bulk (piece) density and apparent (skeletal) density are also determined. At the maximum pressure of 413,700 kPa (60,000 psia) pores as small as 0.003 μ,m are filled. This method is applicable to materials which are essentially non-compressible at the pressures attained during analysis. The sample must also be non-wetting and non-reactive with mercury, and not larger than a right circular cylinder having 25-mm diameter with a length of 25-mm.