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Florida Cleanroom Systems ISO Classification
Per ISO 14644 - 1 Classification of Air Cleanliness

florida cleanroom systems 5ISO/DIS 14644-1 (2010)
, Cleanrooms and associated controlled environments
Part 1: Classification of air cleanliness by particle concentration

  
The new Draft International Standard (DIS) edition of ISO 14644-1, which may be ordered directly through IEST, is the result of a systematic review and includes changes in response to user and expert feedback validated by international enquiry. The title has been revised to “Classification of air cleanliness by particle concentration” to be consistent with other parts of the standard.

   The nine ISO cleanliness classes are retained unchanged, but Table 1 defines the particle concentration at various particle sizes for the nine integer classes. The use of Table 1 ensures better definition of the appropriate particle-size ranges for the different classes. A formula is retained to allow definition of intermediate decimal classes. The standard retains the concept of ultrafine and macro particle descriptors for particle sizes outside the range appropriate for measurement using airborne particle counters.The most significant change is the adoption of a more consistent statistical approach to the selection of number of sample locations and the evaluation of the data collected.

   The number of sample locations compared with the 1999 version of the standard have been changed. The approach allows each location to be treated independently with a 95% level of confidence that at least 90% of the cleanroom or clean zone will comply with the maximum particle concentration limit for the target class of air cleanliness. A reference table is provided to define the number of sample locations required.

   Because a degree of randomness is required, the cleanroom or clean zone is then divided into equal sectors and the sample location placed randomly within each sector.Finally, the annexes have been reordered to improve the logic of the Standard.Please note: In addition to the new DIS version of 14644-1, IEST will continue to sell the 1999 version of the Standard until the new version is adopted as an International Standard (thus replacing the previous Standard). Until then, either the 1999 Standard or the new Draft International Standard can be referenced in a contract. It is up to the customer and supplier to mutually agree on the reference.


Scope of ISO/DIS 14644-1 (2010)


   This part of ISO 14644 covers the classification of air cleanliness in cleanrooms and associated controlled environments exclusively in terms of concentration of airborne particles. Only particle populations having cumulative distributions based on threshold (lower limit) particle sizes ranging from 0.1 µm to 5 µm are considered for classification purposes.

   The use of discrete-particle airborne counting and sizing instruments is the basis for determination of the concentration of airborne particles, equal to and greater than the specified sizes, at designated sampling locations.This part of ISO 14644 does not provide for classification of particle populations that are outside of the specified particle-size range, 0.1 µm to 5 µm. Concentrations of ultrafine particles (particles smaller than 0.1 µm) and macro particles (particles larger than 5 µm) may be used to quantify these populations in terms of U descriptors and M descriptors, respectively.

    This part of ISO 14644 cannot be used to characterize the physical, chemical, radiological or viable nature of airborne particles.Note: The actual distribution of particle concentrations within incremental size ranges is normally not predictable and is typically variable over time.

View list of ISO 14644 Standards

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