HMK-22 Fisher Sub-Siever sizer uses air permeability to fast determine the average particle size of powders. It features simple structure, easy operation, stable performance, good reproducibility therefore being widely used in industries and applications such as powder metallurgy, magnetic materials, hard metal and alloy, tungsten & molybdenum material, gun powder, ceramics, medicine, food, cement, electronics, chemical industry, national defense, space science and technology as well as quality control on import and export powders. It has become the popular means of inspection.