They are extremely inaccurate. But relative measurement is OK - you can see rising or falling pollution. When I put one in kitchen it "died" pretty fast - I thi

They are extremely inaccurate. But relative measurement is OK - you can see rising or falling pollution. When I put one in kitchen it "died" pretty fast - I think the cooking oil grease got onto the sensor and it is game over for me. Shows MAX PM2.5 all the time.