How to use a dust particle counter to detect leaks on HEPA filters?

31/07/2020

    In the air purification industry, HEPA filters have a very important impact on the filtering effect of clean rooms, so the leak detection of HEPA filters is very important. At present, the leak detection of HEPA filters mainly includes sodium flame method, oil mist method, DOP method, fluorescence method, and particle counting method. The following will explain to you how to use a particle counter to detect leaks on high-efficiency filters?

    The so-called dust particle counter is an instrument mainly used to measure the number and particle size distribution of dust particles in a clean environment. It has been used in authoritative organizations such as drug control institutes, blood centers, epidemic prevention stations, disease control centers, and quality supervision institutes. Institutions also include the electronics industry, pharmaceutical workshops, semiconductors, plastics, painting, hospitals, environmental protection, inspection laboratories, and many other industrial production environments. The particle counter is developed from microscope technology. During the development, it has experienced several processes of the microscope, sedimentation tube, sedimentation instrument, centrifugal sedimentation instrument, particle counter, laser air particle counter, PCS nanolaser air particle counter, among which, because of laser The air particle counter has the advantages of fast test speed, wide dynamic distribution, and freedom from human influence. It has become a widely used instrument in many industries in recent years!

    The specific steps of the dust particle counter:

    1. The tested filter must have been tested for air volume and run between 80% and 120% of the design wind speed;

    2. The number of atmospheric dust particles must be determined on the upper wind side of the tested HEPA filter, with particles greater than or equal to 0.5mm as the standard, and the concentration must be greater than or equal to 3.5×`10^4` particles/L;

    3. If the test is an ultra-high efficiency filter, the particles greater than or equal to 0.1mm shall prevail, and the concentration must be greater than or equal to 3.5×`10^6`--3.5×`10^7` particles/L;

    4. If the concentration on the upwind side of the filter does not meet the above requirements, unfiltered air should be introduced; if the test fails to meet the requirements, the particle counter method should not be used for detection;

    5. When detecting leaks, pay attention to placing the sampling port at a distance of 2--3 CM from the surface of the tested filter and moving at a speed of 5--20 MM/S;

    6. Don't forget to scan the entire section of the tested filter, the sealing head glue, and the installation frame in many aspects.

    The above is an introduction to the method of using a dust particle counter in a high-efficiency filter. If you want to learn more about air filters, you can pay attention to Guangzhou RT air filtech Co., Ltd.