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How to use the Mask Bacterial Filtration Efficiency Tester?
2021/02/25
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The function of the mask is to absorb and block particles, smoke, microorganisms, etc. through the filter material without being inhaled by the human body, so as to achieve the purpose of blocking toxic and harmful substances and protecting the human body from infringement.
Different masks have different design requirements, quality evaluation indexes and methods according to their specific users and use environments. Among them, the more important test indexes include Mask Bacterial Filtration Efficiency Tester and particulate filtration efficiency of masks.
Bacterial filtration efficiency
With regard to the bacterial filtration efficiency of masks, only YY0469 medical surgical masks and YY/T0969 disposable medical masks are specified in the relevant standards of masks in China, which is also an important feature that distinguishes them from other masks.
Mask BFE Tester Test method:
1. test principle
Prepare a bacterial suspension with a certain concentration, generate aerosol with specific requirements by an aerosol generator (aerosol flow rate is 2200±500CFE, average particle diameter should be 0.3 μ m, geometric standard deviation of aerosol distribution should not exceed 1.5),
Then pass through the sample to be tested at a certain flow rate, collect the bacteria in the aerosol penetrating the sample, count after culture, and then calculate the filtering efficiency of the sample for bacteria.
2. Test preparation
Before testing, the samples should be pretreated in an environment of 21 5℃ and relative humidity of 85 5% for at least 4h. Staphylococcus aureus ATCC6538 was used to inoculate it into appropriate trypsin soybean broth, and it was shaken and cultured at 37 2℃ for 24h. Then, the above culture was diluted to 5×105CFU/ml with 1.5% peptone.
3. Test steps
A. the test system does not put samples, the air flow of sampler is controlled at 28.3L/min, the time of conveying suspension to sprayer is set at 1min, the air pressure and the running time of sampler are set at 2min, and bacterial aerosol is collected as positive quality control.
B. After the positive quality control test is completed, install the test sample in the clamp at the upper end of the sampler, with the tested surface facing up, and sample according to the procedure.
C. collect air samples in aerosol chamber for 2min as negative quality control.
D. The above processes can be carried out simultaneously through a dual-channel system.
E. after sampling, the agar plate was cultured at 37 2℃ for 48 hours, and the positive pores of bacterial particle aerosol formation unit were counted, and the number of possible impact particles was converted by using the conversion table.
Different masks have different design requirements, quality evaluation indexes and methods according to their specific users and use environments. Among them, the more important test indexes include Mask Bacterial Filtration Efficiency Tester and particulate filtration efficiency of masks.
Bacterial filtration efficiency
With regard to the bacterial filtration efficiency of masks, only YY0469 medical surgical masks and YY/T0969 disposable medical masks are specified in the relevant standards of masks in China, which is also an important feature that distinguishes them from other masks.
Mask BFE Tester Test method:
1. test principle
Prepare a bacterial suspension with a certain concentration, generate aerosol with specific requirements by an aerosol generator (aerosol flow rate is 2200±500CFE, average particle diameter should be 0.3 μ m, geometric standard deviation of aerosol distribution should not exceed 1.5),
Then pass through the sample to be tested at a certain flow rate, collect the bacteria in the aerosol penetrating the sample, count after culture, and then calculate the filtering efficiency of the sample for bacteria.
2. Test preparation
Before testing, the samples should be pretreated in an environment of 21 5℃ and relative humidity of 85 5% for at least 4h. Staphylococcus aureus ATCC6538 was used to inoculate it into appropriate trypsin soybean broth, and it was shaken and cultured at 37 2℃ for 24h. Then, the above culture was diluted to 5×105CFU/ml with 1.5% peptone.
3. Test steps
A. the test system does not put samples, the air flow of sampler is controlled at 28.3L/min, the time of conveying suspension to sprayer is set at 1min, the air pressure and the running time of sampler are set at 2min, and bacterial aerosol is collected as positive quality control.
B. After the positive quality control test is completed, install the test sample in the clamp at the upper end of the sampler, with the tested surface facing up, and sample according to the procedure.
C. collect air samples in aerosol chamber for 2min as negative quality control.
D. The above processes can be carried out simultaneously through a dual-channel system.
E. after sampling, the agar plate was cultured at 37 2℃ for 48 hours, and the positive pores of bacterial particle aerosol formation unit were counted, and the number of possible impact particles was converted by using the conversion table.
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