Summary The issue of ambient air pollution is receiving increasing attention. The concentration of PM2.5 particles in the air is an important criterion for measuring air quality. However, the standard for mea
The issue of ambient air pollution is receiving increasing attention. The concentration of PM2.5 particles in the air is an important criterion for measuring air quality. However, the standard for measuring PM2.5 particles depends on the “standard substance”. Previously, the standard substance could only be imported from abroad. Now, the Beijing Metrology Institute can produce it independently, and the project will apply for a patent.
Yao Hejun, dean of the Beijing Institute of Metrology and Measurement Science, said that China's research on PM2.5 started late. Previously, large-scale testing instruments were first imported from abroad, but these instruments were measured in different ways. Different companies' instruments were in the same environment. Underneath, it is possible to measure different values, which is more confusing. For instrument calibration and monitoring, “standard materials” are required. Previously, “standard materials” were also imported from abroad. “Buy 'Arizona dust' from Arizona, is their sand.” Yao Hejun introduced such particles with PM2. 5 The size is similar, but natural particles also have different sizes, which is not an absolute standard.。
The Beijing Metrology Institute independently developed PM2.5 and dust standard materials and calibration devices. The particle reference material was the first in the hospital. In other words, now we can make absolute standard PM2.5 particles, and a certain number of Once the particles are placed in the air, a known concentration of gas can be obtained and then tested with different instruments to know the accuracy of the instrument and calibrate it. The principle is like measuring a length with a standard ruler.
The particles can be closer to the actual environment and real-world particles, ensuring the accuracy and accuracy of detection, and providing a more accurate basis for environmental governance. The facility participated in the National NQI (National Quality Foundation Major Project) project and will apply for a patent in the next step.
