201-13 National standard GB/T 3249 method for the determination of fisher particle size of metallic and compound powders, and fisher sub sieve sizer.
National standard GB/T 3249 test method for powder particle size of refractory metals and compounds-fisher method is China’s standard for measuring refractory metals and compounds in accordance with international standards. The fisher method mentioned in the standard is a method to measure the average particle size of powder based on the principle of air transmission. This instrument is the HMK-22 Fisher Sub Sieve Sizer. This standard is applicable to the measurement of refractory metals and compounds with particle size of 0.5-50um.