#absorption_unit  a unit for measuring absorption
  supertype:  pm#unit_of_measure_for_a_physical_process (pm)  pm#absorption_measure (pm)  #unit_of_measurement
  subtype:  #sabin  a unit of acoustic absorption equivalent to the absorption by a square foot of a surface that absorbs all incident sound

1 statement is about a direct instance of #absorption_unit: pm#graph1_on_absorption
No  statement uses a specialization of #absorption_unit; click here to add a statement.