Dust Monitoring

Airborne dust particle counting

To follow changing levels of airborne dust particulate matter “PM” continuously, the Dylos Laser Particle Counter #DC-1700-PM displays:

  • a dynamic bar graph of instantaneous particle concentrations, and:
  • numbers displayed for both of the “bi-modal” particle size ranges:
    • Small (0.5-2.5 µm diameter) (fine dust, inhaled more deeply) on the left side, and
    • Large (2.5-10 µm) (coarse dust) on the right;  with
  • numbers displayed for 2 different concentration units, either:
    • mass concentration in micrograms per cubic meter (µg/m3), both Small “PM<2.5” and Large “PM<10”;  or:
    • particle concentration in counts per 0.01 cubic feet, (where Small includes a few Large).  To convert counts into other units:
      • multiply by 100 to get counts per cu.ft. (x100= #/ft3),  or
      • multiply by 4000 to get counts per cu.m (x4000= #/m3),  or
      • multiply by 4 to get counts per liter (x4= #/L) (to get more convenient smaller numbers to work with).

The Dylos can set the operating mode to run as either:

  • continuous (updates display every second, records each minute), or
  • monitor (records 1 minute each hour, shows latest, stores 30 days)

Airborne particle level descriptions

Levels of PM<2.5 are described by the USEPA air quality index (AQI) as:

      • above 300 “hazardous”
      • 201-300 “very unhealthy”
      • 151-200 “unhealthy”
      • 101-150 “unhealthy for sensitive groups”
      • 51-100 “moderate”
      • 0-50 “good”

>see previous page for how particle size matters