for 1 min. The mixed powder obtained was packed in the container of the measuring vessel. The apparent volume of the packed sample was fixed at 140 ml. A rotor was introduced into the packed powder sample at a blade angle of 170° with a rotation speed of 20 rpm and a vertical velocity of 50 mm/s. When the top of the rotor reached a distance of 5 mm from the bottom of the container, as part of the entering process, the rotor was vertically lifted from the powder
layer at a rotation speed of 19 rpm at a blade angle of 178°.