First of all, in the actual environment, since the dust will flow with the flow of the air, it is difficult to ensure that the dust value in any two places is the same even in the same small room, and the Mi Air Purifier sensor is very sensitive, so there will be differences.
Secondly, the sensor output voltages of the two purifiers in the same environment cannot be guaranteed to be exactly the same. When the voltage difference is 0.01V, the dust concentration will differ by 5ug/m², and the voltage error is allowed to be ±0.02V.
Therefore, it is normal for the two purifiers to differ within 20ug/m².
Same Mi Air Purifier in the same environment, such as in a 10,000-level clean room, the difference between any two purifiers will not be much different. If the difference between the two sensors is large, there may be dust accumulation inside the sensor of the purifier with a large reading. You can try to use a vacuum cleaner to clean the dust first.
Secondly, the sensor output voltages of the two purifiers in the same environment cannot be guaranteed to be exactly the same. When the voltage difference is 0.01V, the dust concentration will differ by 5ug/m², and the voltage error is allowed to be ±0.02V.
Therefore, it is normal for the two purifiers to differ within 20ug/m².
Same Mi Air Purifier in the same environment, such as in a 10,000-level clean room, the difference between any two purifiers will not be much different. If the difference between the two sensors is large, there may be dust accumulation inside the sensor of the purifier with a large reading. You can try to use a vacuum cleaner to clean the dust first.