Cleanrooms
Differential pressure measurement
Between rooms of different cleanroom classes, pressure differences between 5 and 20 Pa must be ensured from cleaner room to less clean room. The minimal positive pressure of the cleanroom ensures that no air flows back into the cleaner area from the unclean area when doors are opened. The lowest contamination-level cleanroom itself is also accessed via airlocks for personnel and materials, where strong air currents stir up the particles present and extract them via filter systems. According to DIN EN ISO14644-3, the pressure difference of a cleanroom to the personnel and material airlocks, to any cleanrooms of other purity classes as well as to the surroundings, must be tested
DIN EN ISO 14644-3
DIN EN ISO 14644-3 is an internationally recognized standard that is part of the ISO 14644 series, which relates to clean rooms and controlled environments. The standard specifies the procedures and requirements for testing and evaluating air quality in clean rooms and controlled environments.
The primary purpose of this standard is to evaluate the performance and effectiveness of air handling systems and air filtration systems in clean rooms. The goal is to provide a standardized method for measuring air quality and determining whether a clean room meets the required specifications and standards.
Key Aspects of ISO 14644-3:
- Particle Concentration Measurements: Testing the concentration of particles in the air (at different particle sizes) is an important aspect of maintaining quality in a clean room. This is measured using specialized devices such as air monitors and particle counters.
- Test Procedures:
- Air Sampling Test Methods: The standard describes specific testing methods that must be followed, including the duration of the measurements and the locations where air samples should be taken in the room.
- Measurements Under Different Conditions: The standard differentiates between measurements taken under normal operating conditions, during a testing phase, and in system settings or under conditioned circumstances.
- Performance Evaluation: The results of the measurements are assessed to determine whether the clean room meets the required classification (e.g., ISO 5, ISO 7, etc.) and whether it complies with the necessary standards.
- Airflows and Ventilation Systems: In addition to particle concentration, the effectiveness of airflows and ventilation systems that contribute to maintaining the clean room environment is also evaluated.
- Room Classification: ISO 14644-3 helps determine the correct classification of the clean room by performing air quality measurements and comparing the results to the requirements outlined in other parts of the ISO 14644 series.
Objectives of ISO 14644-3:
- Quality Assurance: It helps organizations ensure that their clean rooms meet the required air quality standards and system functionality.
- Consistency and Reliability: By applying standardized testing methods and measurement procedures, the standard ensures consistent and reliable results.
- Improvement of Safety and Product Quality: Clean rooms are often used in critical environments, such as the pharmaceutical, medical, or electronics industries, where air contamination can have a significant impact on product quality or safety.
Related Standards:
- ISO 14644-1: Defines the classification of air quality based on particle concentration in the air.
- ISO 14644-2: Provides guidelines for the maintenance of clean rooms and controlled environments.
In practice, ISO 14644-3 helps companies and organizations ensure optimal management of clean rooms, which is crucial for a wide range of industrial applications.