The detection standard of the dust particle counter is to classify the air cleanliness level in the clean room (area) and related controlled environment according to the only indicator of suspended particle concentration, and only consider the particle group with a cumulative distribution within the range of 0.1um to 5.0um in particle size limit (lower limit).   
 According to the particle size, it can be divided into conventional particles (0.1um to 5.0um), ultrafine particles (<0.1um) and macro particles (>5.0um).
Air cleanliness classification standard:GB/T16292-1996 (Chinese standard)
Particle size, numerical cleanliness level Maximum allowable number of dust particles/cubic meter Maximum allowable number of microorganisms
≥0.5um≥5um floating bacteria/cubic meter settling bacteria/dish
Class 100 3,500051
Class 10,000 350,000 2,000 1003
Class 100,000 3,500,000 20,000 500 10
Class 300,000 10,500,000 60,000—15
In the past, relevant countries have formulated their own standards, but basically they are based on the various versions of the American standard FS-209, with only the unit system and naming method changed or changed. The naming can be basically divided into two categories:one is to directly name the number of particles greater than or equal to the specified particle size in the unit volume of air or to name them with symbols. This naming method is represented by the American FS-209A~E version, which stipulates that the particle size is 0.5μm, and the concentration of particles with a particle size of ?ge;0.5μm in the air is directly named using the imperial pc/ft3. For example, grade 100 in the standard means that the concentration of particles with a particle size of ?ge;0.5μm in the air is directly named as 100pc/ft3, that is, the number of particles with a particle size of ?ge;0.5μm per cubic foot of air is 100. The second method is to use the number of particles with a specified particle size per unit volume of air as 10n, and name the air cleanliness level according to the index n. This naming method is represented by Japan's JIS B9920, which specifies a particle size of 0.1 μm, and the concentration of particles with a particle size of 0.1 μm in the air (using the international system of units) is 10 pc/m3, which is named level n.