The main performance indicators of the mask bacterial filtration efficiency tester not only meet the requirements of B.1.1.1 test equipment in Annex B Bacterial filtration efficiency (BFE) test method of YY 0469-2011 Medical Outerwear Masks, but also meet the requirements of the United States. According to the requirements of ASTMF2100, ASTMF2101 and European EN14683 standards of the Society for Testing Materials, and on this basis, QINSUN made innovative improvements and adopted a dual gas path simultaneous comparative sampling method to improve the sampling accuracy.Test the bacterial filtration efficiency performance of medical masks in metrology and verification departments, scientific research institutes, medical mask manufacturers and other related departments.
YY0469-2011, YY/T 0969-2013, ASTMF2100, ASTMF2101, EN14683, etc.
Bacterial suspension preparation
Neem Staphylococcus aureus The third generation 24 hours fresh broth culture was diluted with 1.5% phosphate buffer solution containing peptone to prepare a bacterial suspension with a concentration of 5.0 x 105 c/ml.
Before testing, place the sample in the hood in an environment with a temperature of (21±5)°C and a relative humidity of (85±5)% for Each company takes three samples from the same batch for at least 4 hours.
Test of mask filter effect
①According to the standard YY0469-2011 test for medical outer ke masks, connect the two sampling ports of the Henderson pipeline of the BFE system detector to the Anderson six-stage sampler.
②Insert the 90 mm diameter sample plate into the Anderson six-stage sampler. The gasflow rate of the sampler is controlled at 28.3 l/min, the flow rate of the peristaltic pump is 0.180 ml/min. and the fluid supply time is set to 1 min. The time is set to 2 min, the system cleaning time is set to 1 min, and a positive quality control is tested before the test.
③ After the sample test is completed, retest the Positive Quality Control. Then, collect an air sample in the aerosol chamber for 2 minutes as a negative quality control, where the bacterial suspension cannot be delivered to the nebulizer.
④ Turn the agar plate upside down and place it in a (37±2)°C incubator for (48±2) hours. Colony units (positive wells) formed by aerosols of bacterial particles were then counted and positive wells were used. A conversion table converts this to the number of possible impact particles. The formula for calculating the bacterial filtration efficiency of masks: BFE=(C-T)/C×100% (where C: the mean value of positive quality control; T: the sum of the number of samples), Technical requirements for outdoor medical masks (YJ 0469-2011) It is determined that the bacterial filtration efficiency should be greater than 95%.