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    Home > Active Ingredient News > Drugs Articles > Test method and principle of Pao for air filter

    Test method and principle of Pao for air filter

    • Last Update: 2013-11-06
    • Source: Internet
    • Author: User
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    Guide reading: the principle and method of Pao test for air filter the working principle of Pao leak detection is that Pao aerosol occurs on the upper side of the filter to be tested as the dust source, and the photometer is used for sampling on the lower side The scattered light generated by the dust gas through the photometer is converted from photoelectric effect and linear amplification to electric quantity, which is quickly displayed by the microammeter The collected air sample passes through the diffusion chamber of the photometer Due to the difference of light intensity caused by particle diffusion, the relative concentration of aerosol can be measured by the photometer after measuring the light intensity In the Pao test, the penetration rate of the filter is actually measured, and the relationship between the filter efficiency and the penetration rate is as follows: k = (1-α) × 100% K: filter penetration rate α: filter efficiency Pao method leak detector aerosol as the dust source, cooperating with the aerosol photometer Commonly used aerosol: dioctyl phthalate (DOP), due to its mutagenicity, is mostly polyalphaolefin (PAO) Pao leak detector aerosol generator: a device that produces smoke Aerosol photometer: an instrument for measuring and displaying aerosol concentration In the air purification project, Pao method is mainly used for the leakage test after the installation of filter and sub filter, especially for the laminar or turbulent flow requiring 10000 or higher cleanliness, it is very important to carry out the leakage test Pao leakage test is aimed at the filters on laminar flow table, laminar flow hood, self purifier, sterile tunnel and filling line equipment Pao leakage test of filter is mainly to check small pinholes and other damages in filter medium, such as frame seal, gasket seal and leakage on filter frame When the reading on the photometer (penetration rate) exceeds the standard, the filter is deemed to be unqualified, and it shall be supplemented or replaced The leakage rate at the filter seal shall be 0 The leakage of filter material is allowed to be repaired, but the area of single leakage shall not be greater than 1% of the total area, and the area of all leakage shall not be greater than 5% of the total area, otherwise, it must be replaced.
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