Masks are an important anti-epidemic material in the novel coronavirus epidemic. While the demand is increasing, relevant media have reported that the quality of masks in many countries has the problem of substandard filtration efficiency. Mask production-related companies and testing institutions should strive to keep unqualified medical masks out. Choosing a suitable mask testing instrument is a key step in controlling the quality of masks from the source. Guangzhou Biaoji Mask Instrument Consultant will take you to understand masks How to detect the filtration efficiency, and how to choose the appropriate testing equipment.
According to the definition of relevant standards, filtration efficiency refers to the percentage of particulate matter removed by the filter element under the specified detection conditions.
The measurement principle is to measure the number or concentration of particles inside and outside the mask or on both sides of the mask when a certain flow of air passes through the filter material of the mask. The ratio of the internal particles/concentration of the mask divided by the number of external particles/concentration of the mask is the filtration efficiency.
BFE refers to the efficiency of bacteria concern, the target particle size is 3 microsurgery, which can block Block pollen and droplets;PFE stands for the filtration efficiency of particulates, and the targeted particulate size is 0.1 micron, which can resist Block influenza, SARS and other viruses
The particulate matter filtration efficiency can be divided into non-oily particulate matter filtration efficiency (also known as "salt media filtration efficiency") and oily particulate matter filtration efficiency.
Oily particulate matter: smoke produced by combustion such as cigarettes, coal, garbage incineration, automobile exhaust, etc.
Non-oily particles: microorganisms, droplets, viruses, etc.
FE stands for Virus Filtration Efficiency and targets particles with a size of 0.1 to 5 microns.
At present, the international dust mask mainly implements two standards, namely the American standard and the European standard. The standard of my country's protective mask mainly refers to the American standard.
Among them, NIOSH will prevent particulate respirators or filter originals according to the nature of the object to be protected and the length of the
Divided into three categories: N, R, and P: N is used to protect non-oily particles; R and P can be used to protect non-oily particles and
Oily particulate matter (R type filter element has a shorter use time limit than P type filter element, generally 8h, P type filter
The use time of the original is longer, and the manufacturer usually makes the use time recommendation).
Generally use DOP or paraffin oil or other oil particles with equivalent properties.NaCI aerosols are used for the detection of the filtration efficiency of salt particles, and the detection of the filtration efficiency of oily particles is one
Combining different domestic and foreign standards, Guangzhou Biaoji launched two different configurations of particulate matter filtration efficiency testers
TYPE 1:
Configure a set of aerosol generators (NA CL salt aerosol generator, DEHS oil aerosol generator)
It is equipped with two laser dust particle counters, KN95 and plane mask fixture. Suitable for testing 0~99.9% grade filter material test, suitable for filter materials, flat masks, N95 masks and other filter materials are suitable
Customers can choose a suitable mask testing instrument according to the actual needs of the mask. More series of laboratory testing instruments can contact us immediately, and the professional mask testing consultant of GBPI will serve you online 24 hours a day.