Cleanroom testing

The testing content mainly includes the following aspects:

1. Air cleanliness testing: This is the most basic testing item, mainly measuring the quantity and size of suspended particles in the air. Particle counters are usually used to sample at different locations and evaluate cleanliness levels based on the number of particles of different sizes per unit volume. International standards such as ISO14644-1 classify cleanrooms into multiple levels, with smaller numbers indicating higher cleanliness. For example, ISO 5 requires that the number of particles greater than or equal to 0.5 microns per cubic meter of air should not exceed 3520.

2. Temperature and humidity detection: Many production processes are very sensitive to temperature and humidity. Temperature fluctuations may cause material expansion or contraction, while abnormal humidity may lead to static electricity accumulation or microbial growth. The detection usually uses calibrated temperature and humidity recorders to continuously monitor at multiple points, ensuring that the environmental conditions are always within the set range.

3. Differential pressure monitoring: Cleanrooms usually prevent external polluted air from entering or internal pollutants from escaping by maintaining internal positive or negative pressure. For example, in the pharmaceutical production area, positive pressure needs to be maintained inside the workshop to prevent unfiltered air from entering from the outside. Differential pressure detection uses a micro differential pressure gauge to measure the pressure difference between different areas, ensuring that the airflow direction meets the design expectations.

4. Wind speed and airflow uniformity test: An efficient air filtration system needs to provide stable and uniform airflow to effectively remove particulate matter. The commonly used thermal anemometer for wind speed detection measures whether the wind speed value meets the requirements at the air supply outlet or work area. The airflow pattern test is conducted through smoke experiments or particle image velocimetry to observe whether the airflow direction is reasonable, whether there are eddies or blind spots.

5. Microbial testing: In certain industries such as food or bioproducts, additional attention should be paid to microbial contamination. Collect samples and culture them in the laboratory using methods such as settling bacterial method, planktonic bacterial sampler, or surface sampling (contact plate), and calculate the number of bacterial colonies. This test ensures that the environment does not cause biological pollution to the product.