9.%20Cleanroom%20Testing%20and%20Monitoring

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9. Cleanroom Testing and Monitoring
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Purposes for initial test

• Fulfill the design
• working correctly and achieving the contamination
  standards
• Bench-mark
• establish the initial performance of the room to
  compare the results of routine check or
  contamination problem in the future.
• Training the staff (most important)
• initial testing is to familiarize and train the
  staff.
• Only opportunity to understand how their
  cleanroom works and learn the methods used to
  test.

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initial test

• Time
• been built/ going to hand over/ reopen
• Tested standards
• ISO 14644-1.
• Monitoring
• to regularly check the room at the time
  intervals set by ISO 14644-2

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Principles of Cleanroom Testing

• Quantity
• Turbulently dilute--air volume (supply and
  extract)
• Unidirectional remove air velocity
• Direction (flow direction)
• from clean area ? less-clean areas to minimise
  the movement of contaminated air.
• Quality
• the air will not add significantly to the
  contamination within the room
• Distribution inside cleanroom
• the air movement has no areas with high
  concentrations of contamination.

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Cleanroom Tests
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• Air supply and extract quantities
• turbulently ventilated cleanrooms? the air supply
  and extract volumes
• unidirectional airflow ? air velocity.
• Air movement control between areas direction
• The pressure differences between areas are
  correct.
• The air direction through doorways, hatches, etc.
  is from clean to less-clean.

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• Filter installation leak test
• a damaged filter
• between the filter and its housing or
• any other part of the filter installation.
• Containment leak testing
• Contamination is not entering the cleanroom
  through its construction materials.

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• Air movement control within the room
• turbulently ventilated check that there are no
  areas within the room with insufficient air
  movement.
• unidirectional airflow check that the air
  velocity and direction throughout the room is
  that specified in the design.
• Airborne particles and microbial concentrations
• final measurements of the concentration of
  particles and micro-organisms

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• Additional tests
• temperature
• relative humidity
• heating and cooling capabilities of the room
• sound levels
• lighting levels
• vibration levels.

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requirements

• Guides provided by
• the American Society Heating Refrigeration and
  Airconditioning Engineers (ASHRAE) in the USA,
  and
• the Chartered Institute of Building Services
  Engineers (CIBSE) in the UK.

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Testing in Relation to Room Type and Occupation
State

• The type of tests to be carried out in a
  cleanroom depends on whether the room is
  unidirectional, turbulent or mixed airflow
• as-built ---in the empty room,
• at rest --- the room fitted with machinery but
  no personnel present or
• fully operational---these occupancy states are
  discussed more fully in Section 3.4 of this book.

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Re-testing to Demonstrate Compliance

• The cleanroom checked intervals, these intervals
  being more frequent in higher specified rooms
  ISO 14644-2

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Monitoring of Cleanrooms

• Use risk assessment to decide what monitoring
  tests should be done and how often. The variables
  that are most likely to be monitored are
• air pressure difference
• This might be necessary in high quality
  cleanrooms such as ISO Class 4, and better.
• airborne particle count
• This might be necessary in high quality
  cleanrooms such as ISO Class 4, and better.
• where appropriate, microbiological counts.