“…The generated impinging flow on a plate from a converging nozzle operating under sonic conditions results in the creation of a standoff shock whose properties can be changed by varying impactor geometry (distance between nozzle and plate x and diameter of nozzle d) and operating conditions (Alvi et al, 2002;Delamora et al, 1990aDelamora et al, , 1990bJurcik et al, 1989;Powell, 1988;Sislian et al, 2009). In traditional impactors (Hering et al, 1978(Hering et al, , 1979, the aerosol is collected by impaction on a flat surface.…”