Surveillance of PM2.5 instruments looks like landscape lights to monitor instantaneous values

At the just-concluded fifth meeting of the 11th National People's Congress in the province, PM2.5 testing, which received much attention from all walks of life, was first written into the “Government Work Report.” On the 17th, the Xi’an Twelfth Party Congress was opened. It is also clearly stated that it is necessary to “establish a PM2.5 index detection system for air quality”. At present, the province's monitoring of PM2.5 has been carried out one after another. So what kind of instrument is it?

According to imagination alone, PM2.5 monitors used for precision testing should be said to be a giant. However, when reporters saw it at a monitoring site in the martyrs’ cemetery in Xi’an City yesterday afternoon, they discovered that the “mysterious instrument” actually looked ordinary and looked like a landscape light.

■ An engineer who can monitor instantaneous values ​​and is responsible for the automatic monitoring of the atmosphere, Wang Zhao introduced that the PM2.5 monitoring method currently uses the shock balance method. That is, the sample is sucked into the atmosphere through the sampling head located on the roof of the building. The atmosphere reaches the indoor data through the above-mentioned suction pipe. Analyze the platform on the instrument, and then pass through a filter smaller than a dime coin (there is a small round hole below the filter). Below the filter there is a column that leads to the display, when particles in the atmosphere pass through When the small round hole in the filter membrane reaches the column, the column will vibrate, and then there will be a corresponding value, that is, the PM2.5 concentration value at that time.

The indoor data analysis instrument has a display screen that is almost the same size as the tablet computer screen, and the data is changing. Wang Zhao said that the number on the display is the monitored PM2.5 data. According to reports, the PM2.5 monitor is an imported instrument. It can display the PM2.5 monitored during six periods of instantaneous, 30 minutes, 1 hour, 8 hours, 12 hours and 24 hours. Numerical value.

It is understood that at present, Xi'an City has already started monitoring and monitoring of PM2.5 at substations of 6 monitoring stations. The martyrs' cemetery monitoring site began monitoring from August last year.

■ Pilot monitoring data reporting According to Wang Zhao, although the monitoring of PM2.5 is simple from the aspect of appearance and monitoring principle, the actual operation is not simple, and the internal design of the instrument is also very complicated. Because Xi’an is one of the first cities in the country to pilot monitoring of PM2.5, the PM2.5 values ​​that were piloted and monitored have not only been collected in Xi’an Environmental Protection Monitoring Station, but also reported to the national authorities on a daily basis. Values ​​for their research and analysis.

It is understood that the location of PM2.5 monitoring sites is also very particular about. He Feili, director of the provincial environmental protection department, introduced that the monitoring point of PM2.5 is based on the level of economic development of the city and the size of the city. Distribution points should be as reasonable and representative as possible, and at the same time, every point should be striving. Can reflect the real situation of a region.

At present, Xi'an has begun pilot monitoring of the six sites are built in Xi'an. The relevant personnel of the Xi'an Environmental Protection Bureau said that PM2.5 monitoring is a systematic project. Especially for the later maintenance, it requires a lot of manpower, material resources, and financial resources. If human, material, and financial resources keep up, Xi’an wants to quickly The environmental monitoring points are equipped with PM2.5 monitoring equipment and start city-wide monitoring.

â–  In April last year, people began to monitor the overcast days in Xi'an. People's feelings were very low. Many people also asked questions: "In this weather, the PM2.5 content in the air does not know exactly how much it will harm the human body. How big is it; since it has started monitoring PM2.5, what exactly is the source of PM2.5?"

According to Wang Zhao, although Xi’an City started pilot monitoring of PM2.5 as early as April of last year, due to the influence of equipment and funds, the current monitoring point coverage and site selection cannot fully reflect PM2 in Xi’an. The case of .5, and the analysis of the origin of particulate matter has at least a long period of time to produce results, so the data that has been monitored has not yet officially begun to be analyzed.

He also said that in fact, a large part of the source of atmospheric pollution is caused by human activities. At present, the pollution sources of Xi’an’s air pollution, including PM2.5, are mainly motor vehicle exhaust, coal-burning, dust, etc., and people can drive down private cars. Traveling, reducing the use of coal briquettes and other methods to reduce the pollution of the atmosphere.