Cleanroom suitability
Encyclopedia
Cleanroom suitability describes the suitability of a machine, operating utility, material, etc. for use in a cleanroom
Cleanroom
A cleanroom is an environment, typically used in manufacturing or scientific research, that has a low level of environmental pollutants such as dust, airborne microbes, aerosol particles and chemical vapors. More accurately, a cleanroom has a controlled level of contamination that is specified by...

, where air cleanliness and other parameters are controlled by way of technical regulations in accordance with ISO 14644
ISO 14644-1
ISO 14644-1, Cleanrooms and associated controlled environments—Part 1: Classification of air cleanliness, was the first ISO 14644 International Standard prepared by ISO Technical Committee 209...

.

Cleanroom suitability is a subdomain of cleanliness suitability
Cleanliness suitability
Cleanliness suitability describes the suitability of operating materials and ventilation and air conditioning components for use in cleanrooms where the air cleanliness and other parameters are controlled by way of technical regulations...

 and primarily describes the particle emission behavior of a machine or operating utility (test piece).

Testing

The aim of cleanroom suitability tests is to determine the suitability of machines and operating utilities (air conditioning, venting, etc.) for use in cleanrooms. The tests must be carried out using measurement techniques as particle emission behavior cannot be adequately assessed by the naked eye or similar means. No metrological tests are required if there are obvious flaws in machines and operating utilities, such as rust or the presence of porous or completely unsuitable materials (wood, etc.).

Tests to assess the cleanroom suitability of a machine or operating utility using measurement techniques are performed in a cleanroom in order to be certain that the particles detected are emitted from the test piece. The test cleanroom has to be at least one class cleaner that the desired suitability of the test piece, otherwise it would not be possible to relate the particles detected to the test piece in question. An exception to this is when determining the suitability of a test piece for use in Class 1 cleanrooms in accordance with DIN EN ISO 14644-1: such tests have to be carried out in a Class 1 cleanroom because no other cleanroom classes are defined which are better than this. The test cleanroom must have a low-turbulence airflow (often known as laminar
Laminar flow
Laminar flow, sometimes known as streamline flow, occurs when a fluid flows in parallel layers, with no disruption between the layers. At low velocities the fluid tends to flow without lateral mixing, and adjacent layers slide past one another like playing cards. There are no cross currents...

 in this context) in order to prove high air cleanliness classes and also accurately locate particle sources.

Particle counter
Particle counter
A particle counter is an instrument that detects and counts particles. By its very nature a particle counter is a single particle counter, meaning it detects and counts particles one at a time. The nature of particle counting is based upon either light scattering or light obscuration...

s are utilized as measurement devices in order to determine particulate contamination with regard to geometrical size, quantity, distribution, chronological progression and location.

The cleanroom suitability of a material describes its particle emission behavior. However, as particle emission from materials can only be assessed under stress conditions, model tests on material pairings have proved to be valuable in order to obtain reproducible, comparable results. Particle emission behavior tests have to be carried out under the same conditions as for machines and operating utilities, and optical particle counters are also implemented.

External links

  1. Cleanroom Suitable Equipment Database
  2. Cleanroom Suitable Materials Database
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