Eight-stage Andersen cascade impactor (ACI) is a multi-stage, porous impact sampler for aerodynamic characteristics determination for inhaled fine particles, consisting of multi-stage cascade impactors and membrane in the last stage. When determining MDIs and Sprays, the top cover is connected to the induction port and generator via an adapter. When determining DPIs, a pre-separator should be mounted to the top to collect large quantities of non-inhalable powder particles. It conforms to USP and Ph. Eur. as well as aerodynamic characteristic determination of inhaled fine particles of ChP2020.