Clean Room Quiz 1

Clean Room Quiz 1 -Question & answers on Clean Room

Question: What is the definition of an “airborne particle”?

Answer: An airborne particle is described as a solid or liquid object suspended in the air, whether viable or non-viable, falling within a size range spanning from 1 nanometer (nm) to 100 micrometers (μm).

Question: How is the “count median particle diameter” defined, and what does it signify?

Answer: The count median particle diameter denotes the median particle size based on the number of particles. Specifically, half of the particle number is contributed by particles smaller than the count median size, while the remaining half is contributed by particles larger than the count median size.

Question: What is “particle concentration” and how is it measured?

Answer: Particle concentration indicates the number of individual particles present per unit volume of air. It is quantified by counting the number of particles within a given volume of air.

Question: Can you explain the concept of “designated leak”?

Answer: A “designated leak” refers to the maximum allowable penetration of particles through a leak in a filter system, established through mutual agreement between the customer and supplier. This penetration must be detectable during the scanning of a filter installation using light scattering airborne-particle counters (LSAPC) or aerosol photometers.

Question: What constitutes a “final filter”?

Answer: A “final filter” is defined as the filter positioned at the final stage before air enters a cleanroom or clean zone, serving to remove particles from the air stream before it reaches the designated area.

Question: What is the significance of a “test aerosol”?

Answer: A test aerosol is a gaseous suspension containing solid and/or liquid particles with a known and controlled size distribution and concentration. It is utilized to challenge filters or installed filter systems in order to assess their effectiveness.

Question: What is the definition of “particle size,” and how is it determined by particle-sizing instruments?

Answer: Particle size is defined as the diameter of a sphere that produces a response equivalent to the response generated by the particle being measured, as detected by a given particle-sizing instrument. For light-scattering airborne-particle instruments, the equivalent optical diameter is commonly used.

Question: What is a “filter system” according to ISO14644 part 3?

Answer: A “filter system” is defined as an assembly comprising a filter, frame, and other support mechanisms or housing components. It is designed to capture and remove particles from air or fluid streams.

Question: Can you explain the concept of a “final filter” according to ISO14644 part 3?

Answer: A “final filter” refers to the filter positioned at the ultimate stage before air enters a cleanroom or clean zone. It serves as the last line of defense, removing any remaining particles from the air stream before it reaches the designated clean area.

Question: What is meant by an “installed filter system leakage test”?

Answer: An “installed filter system leakage test” is conducted to verify the proper installation of filters by ensuring the absence of bypass leakage within the filter installation. This test also confirms the absence of defects and leaks in both the filters themselves and the associated grid system.

Question: How is a “leak” defined for air filter system?

Answer: In the context of an air filter system, a “leak” refers to the penetration of contaminants that exceed an expected downstream concentration due to lack of integrity or defects within the system.

Question: What is the purpose of “scanning” in the filter testing?

Answer: “Scanning” is a method used to reveal leaks in filters and components of units. It involves moving the probe inlet of an aerosol photometer or a light-scattering airborne-particle counter in overlapping strokes across a defined test area to detect any potential leaks.

Question: How is the “air exchange rate” calculated?

Answer: The “air exchange rate” is calculated by expressing the number of air changes per unit of time. This calculation is achieved by dividing the volume of air delivered within a specified time period by the volume of the cleanroom or clean zone being assessed.

Question: What is meant by “non-unidirectional airflow”?

Answer: “Non-unidirectional airflow” refers to an air distribution system where the supply air entering a cleanroom or clean zone mixes with the internal air through induction rather than following a single, consistent direction.

Question: How is the “uniformity of velocity” defined in the context of airflow patterns?

Answer: The “uniformity of velocity” pertains to a unidirectional airflow pattern where point-to-point readings of airflow velocity (both speed and direction) remain within a defined percentage of the average airflow velocity.

Question: What is the “discharge time” referring to in the context of the provided text?

Answer: The “discharge time” represents the duration required for the voltage of an isolated conductive monitoring plate to decrease to its original charged level, either positive or negative.

Question: Can you explain the function of an “aerosol generator”?

Answer: An “aerosol generator” is an apparatus capable of producing particulate matter within a specific size range (e.g., 0.05 μm to 2 μm) at a constant concentration. This particulate matter can be generated through various methods such as thermal, hydraulic, pneumatic, acoustic, or electrostatic means.

Question: What is the role of an “airflow capture hood with measuring device”?

Answer: An “airflow capture hood with measuring device” is a tool equipped with apparatus designed to cover a filter or air diffuser entirely and collect the air flow. This device allows for direct measurement of the air volume flow rate.

Question: What is meant by the term “as-built” in relation to cleanroom or clean zone conditions?

Answer: “As-built” refers to the condition of a cleanroom or clean zone where all services are connected and functioning, but no equipment, furniture, materials, or personnel are present.

Question: How is the “at-rest” condition defined in the context of cleanroom or clean zone operations?

Answer: The “at-rest” condition signifies that the cleanroom or clean zone is complete with installed equipment operating as agreed upon, but no personnel are present within the space.

Question: Can you explain the concept of “operational” in the context of cleanroom or clean zone management?

Answer: “Operational” refers to the agreed-upon condition where the cleanroom or clean zone is fully functional as specified. In this state, equipment is operational, and the designated number of personnel is present and conducting activities according to established protocols.

Clean Room Quiz 3