Working principle of air quality detection module
The module detects the polluted gas in the air by measuring the
sensor, temperature and humidity
Signal processing and output of pollution data to achieve the
detection function of air quality.
●Preheating process
Module power on preheating stable stage, this stage sensor needs to
be heated to a stable state, this time depends on the environment
The lower the temperature is, the longer the preheating time is.
The module is set to 3 minutes, during which the module will
dynamically calculate the preheating time, and the preheating
process can be completed in 5 seconds at least, so as to reduce the
cost of battery powered products
Power consumption. Although the module shortens the warm-up time,
the module will sacrifice sensitivity at this moment
The module preheating time should be extended as far as possible
●Normal measurement
After the module preheating is completed, the module starts to work
normally, and collects sensor data continuously, and then keeps it
clean with the saved one
The data of clean air are calculated to calculate the environmental
pollution value or pollution level.
●Automatic calibration of clean air standard
In order to maintain the high sensitivity of the module and be
affected by the sensor drift, the module will automatically update
according to the algorithm
The clean air reference value is stored in the memory.
●Saturation correction
Under the condition of air pollution, if the air is filtered
through the filter device through the equipment. Air pollution
However, the odor can be filtered through the filter, but the
organic volatile gas in the polluted air can not be filtered, such
as hydrogenation
However, the sensor can still detect relatively high data, which
leads to the inconsistency with the actual feeling of the human
body.
In order to avoid this state, an automatic saturation correction
algorithm is added to the module to change the output value or
level
Don't let the human body feel similar to the actual output
Although saturation correction can bring better correction to a
certain extent, it is very stable in the long term
In a given environment (such as a public toilet with heavy odor),
saturation correction will cause the output data to be clean. all
However, considering the particularity of the environment,
saturation correction algorithm is still introduced.
