Datasheet

9
"concentration" is a figure that has physical meaning. It's calculated from the characteristic graph
below by using the LPO time.
Here is a figure we tested dust concentration in office :
We can see the concentration of dust is very low in the evening, but it's higher in the afternoon.
Maybe you can set a threshold value while the concentration is beyond a value. Also, if you wanna
set the sensor more sensitive you can add a fan on the sensor, and add a 10k resistor between
the Pin5 and Ground. More information please visit the blog of A.J.