ODM2 Units Type Controlled Vocabulary ODM2 Working Group A vocabulary for describing the type of the Unit or the more general quantity that the Unit represents. Specific surface area Specific surface area "SSA" is a property of solids which is the total surface area of a material per unit of mass. It is a derived scientific value that can be used to determine the type and properties of a material (e.g. soil, snow). It is defined by surface area divided by mass (with units of m²/kg). Mechanics Wikipedia http://dbpedia.org/page/Specific_surface_area