In any more or less large industrial city and its surroundings, the air is polluted with a lot of suspended particles. And it’s mostly third-party substances handled by industry, plus other man-made components, decay products from combustion, and all the rest.
In general, all this – very bad for health, and in some cities, people even have to wear masks, in the case of a particularly active phase of production and a particular configuration of the wind rose.
Assessment of air quality in such places is of course carried out, but not in all regions and not as often as we would like. The reason for this is the high cost of analysis and the need to use in-house and mobile laboratories. German scientists from the Karlsruhe Institute of Technology offered their solution.
This solution is a small module for a cell phone, which evaluates the air quality by using the camera and flash of the device. Of course, it is not possible to use the module on a phone without a camera and without a flash.
The module itself is attached to the back of the smartphone with a magnet, and the holes in the module should be placed over the flash and the camera of the smartphone.
Everything works quite simply. A person presses the “take a picture” button (setting the flash mode), the flash goes off and the light from it travels to the camera sensor via fiber optics.
The module also has a passive air intake, through which the light from the flash passes before reaching the lens of the camera. The more suspended particles in the sampled air sample – the more light is scattered.
For his module (its body, by the way, printed on a 3D printer), scientists have developed and appropriate application that analyzes the images obtained by the camera, calculating the number of particles in the air by the brightness of pixels in the resulting image. According to the specialists, the brightness of the pixels in the photo allows for a fairly accurate calculation of air pollution, for which a special algorithm has been developed.
After testing their device, the scientists compared their own atmospheric results with those of regular air quality stations. The results came together quite accurately.
Of course, the device has limitations. In particular, it can fix atmospheric pollution when the concentration of suspended particles is up to about 1 milligram per cubic meter. Moreover, particles less than 10 microns (fine dust is the most dangerous, by the way) are not detected by the device yet.
Now scientists are working on improving the characteristics of the device, so that it would be possible to take into account the fine dust fraction.
According to the developers, their device can be useful for all people, users of mobile devices, who are concerned about the quality of the atmosphere of their city. With such a device and its application, it would be possible to quickly map the atmosphere of the city/region, after which the results would be provided to the relevant services.
