PM2.5 is a scale for measuring real time air quality. Its values vary from 0 to 500.
The PM2.5 indication is connected to your Philips Air Purifier’s air quality light ring/bar to inform you in real time about the quality of the ambient air.
The different colors indicate the following:
* Blue: good
* Blue-Violet: fair
* Red-Purple: unhealthy
* Red: very unhealthy