Question about Xiaomi MI Air Purifier Pro H

My experience with this device is analogous to "Stardustone".

The air quality data is correct. The air purifier is not superfluous, because if it indicates 001, the air inside is clean. It also filters dust particles. There are a few "test possibilities" to see how effectively the air is cleaned. At midnight on New Year's Day, when there is more lightning and banging outside, open the window and the displayed values should be 60 or more. Or open a bag of microwave popcorn in the same room. That will bring the readings up to over 200. Cooking with fat or oil, I had my highlights with that, the values reached over 270. The air purifier will then automatically use a higher fan level to bring the value back to 001. No, the air purifier is by no means superfluous, even if you open the windows for ventilation in winter months, the values rise to 020 or higher within minutes, even in the country. In the city, it should generally have higher values than 001 outside. If it is 001 in the flat, that shows that the air purifier is working, and working very well.