I am using a Grove Dust Sesnor to log and graph the parlicle concentration in the atmosphere. The sensor is connected to a Raspberry Pi which then calculates and logs the output for graphing.
The Dust Sensor measures particles greater than 1 micron and the display is in pcs/litre.
I have found that the visibility is generally comparable to the amount of particles in the air, so a high Dust count will generally mean a lower visibility. I have included the wind direction as well for interest.