How is the Particulate Filtration Efficiency (PFE) test conducted?

The Particle Filtration Efficiency (PFE) test is a test that uses a series of standardized procedures and equipment to evaluate the effectiveness of masks and other filtration devices in filtering particulate matter. The following are the usual steps and methods fFirst, you need to prepare a sample of the filter material to be tested, which is usually a part of the mask or the filter material in the filter equipment.

 

2. Particulate matter solution preparation: 

Prepare a solution with a known particle matter concentration. These particles are typically polyethylene or polymethylmethacrylate particles, typically ranging from 0.1 to 5 microns in diameter. The particle size range of these particles covers the size of particles in the general air.

 

3. Testing equipment: 

PFE testing typically uses an optical particle counter (OPC) or similar equipment to measure the size and number of particles. These devices can accurately measure the distribution of particles in different diameter ranges.

 

4. Testing process: 

The sample material is placed in the test equipment, and then a particle solution with a known particle concentration is sprayed onto the sample. These particles simulate airborne particles produced when breathing to evaluate how well the sample filters these particles.

 

5. Particle counting: 

After spraying the particle solution, the test equipment measures the number of particles that pass through the sample, while using an external reference number of particles in the air as a control. Particle filtration efficiency can be calculated by comparing the number of particles passing through the sample to the total number of particles.

 

6. Calculate PFE value: 

Particle filtration efficiency is usually expressed as a percentage, which refers to the ratio of the number of filtered particles to the total number of particles after passing through the test sample. For example, a PFE of 95% means that the sample that passed the test was able to filter out at least 95% of the particles.

 

Through these test steps and methods, the filtration effect of masks and other filtration devices on particles in different diameter ranges can be evaluated and their particle filtration efficiency can be determined.