Home » About Us » Cleanliness Class

Every country has its own specification for the cleanliness class, but the most frequently used standard is the American federal standard of 209. Then, we just introduce the standards of 209D, 209E and of the other country.

The largest difference between the standard of 209E and the other standards such as 209 is that the representation unit of 209E has the metric unit included. The clean room level is expressed with the first letter of M, such as M1, M1.5, M2, M2.5, M3 and so on. It is stipulated to match with the standardization of international metric unit. The Arab number after the M is calculated in this way. First, we measure the concentration of dust particle for per cubic meter. The diameter of the particle is not less than 0.5μm. The number of the dust particle is showed with the bottom number of 10. Then the power exponent is the number after the M. If the dust particle number is a middle value between two numbers with power, then the number after M is expressed with 1.5, 2.5, 3.5 and so on.

The American federal standard of 209D adopts the Pc/ft3 as the unit. But the Japanese standard uses the metric unit and the counting standard is the particles with the diameter of 0.1μm. Then the cleanliness level is expressed with Class 1, Class 2 to Class 8. The highest level is Class 1 and the least level is Class 8. The dust particle number is counted with the unit of Pc/m3 and is expressed in the way of 10 to the power of n. Then the n is the number in the level.

Main Products