Comparison and classification of disposable masks
Use the disposable mask to fix the handheld particle tester on the desktop, place the air outlet of the hair dryer facing the sampling port of the particle tester at a distance of about 20cm, turn on the cold air of the hair dryer and adjust it to a low-grade wind;
Turn on the particle tester and measure the environment (in a closed room), that is, the particle concentration at the sampling port of the particle tester. The test time is 20 seconds. After the measurement, record the number of 0.3-micron and 2.5-micron particles respectively;
Cover the sampling port of the particle tester completely with the N95 mask or other masks, and measure the concentration of particles filtered by the filter material of the mask. The test time is 20 seconds. After the measurement, record the number of 0.3-micron and 2.5-micron particles respectively;
Repeat process 2 and 3 for the remaining 4 masks.
The following pictures show each type of mask and the corresponding 0.3-micron and 2.5-micron particle removal rates, which can be seen:
N95 masks have high removal rates for 0.3-micron and 2.5-micron particles, both exceeding 90%;
The two three-layer medical masks (the 2nd and 3rd) have 90% and 51% removal rates for 0.3-micron particles, respectively, and 100% and 75% for 2.5-micron particles;
The two ordinary dust masks performed poorly. The three-layer black mask had only 20% removal rate for 0.3-micron particles and 60% for 2.5-micron particles; the two-layer blue mask had even 0.3-micron removal rate. If it is 0 (invalid), the removal rate of 2.5 micron particles is only 42%.
Mask classification:
N series: N stands for Not resistant to oil, which can be used to protect non-oily suspended particles for no time limit.
R series: R stands for Resistant to oil, which can be used to protect non-oily suspended particles and sweat oily suspended particles for eight hours.
P series: P stands for oil Proof, which can be used to protect non-oily suspended particles and sweat oily suspended particles without time limit. When the carrier of some particles is oily, and these substances are attached to the electrostatic non-woven fabric, they will reduce the electrical properties and allow fine dust to penetrate. purpose of dust.
Summarize:
Whether it is N95 mask, or R95, P95 and N99, R99, P99 with higher bacteria filtering function, or even N100, R100 and P100 and other types of masks, they can effectively filter suspended particles or germs. In addition, the EU standard FFP1, FFP2 and FFP3 industrial masks can also effectively filter out particles or germs.
