The Quantachrome Autoscan 60 Mercury Porosimeter is used to measure the open pore size distribution in consolidated samples. In this system, mercury is forced into evacuated surface pores by applying high pressure to the specimen. The pore radius at a given applied pressure can be calculated from the Washburn equation, which shows an inverse relationship between the intruded pore radius and the applied pressure. The instrument can measure pore radii varying from ~100 µm to 1.8 nm for unconsolidated and consolidated particulate materials.