Activity Median Aerodynamic Diameter AMAD 1
Activity Median Aerodynamic Diameter AMAD 1 :
Medicine. The value of aerodynamic diameter5 such that 50% of the airborne activity in a specified aerosol is associated with particles smaller than the AMAD, and 50% of the activity is associated with particles larger than the AMAD. Used in internal dosimetry for simplification, as a single 'average' value of aerodynamic diameter representative of the aerosol as a whole. The AMAD is used for particle sizes for which deposition depends principally on inertial impaction and sedimentation (i.e. typically those greater than about 0.5 µm). For smaller particles, deposition typically depends primarily on diffusion, and the activity median thermodynamic diameter (AMTD- defined in an analogous way to the AMAD, but with reference to the thermodynamic diameter5 of the particles - is used
