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How to Calculate Particulate Matter

Particulate matter refers to very small particles of liquids or solids that are suspended in air. It is made up of dust, acids, exhaust, smoke, metals and organic chemicals. Particulate matter is divided into two categories: coarse particles and fine particles. Coarse particles have a diameter between 2.5 and 10 micrometers. Coarse particulate is often abbreviated as PM 10. Fine particles have a diameter less than 2.5 micrometers, and are abbreviated as PM 2.5. Both types of particles can have a negative impact on human health when they are inhaled. Especially for those with preexisting heart and lung conditions.

Things You'll Need

Ambient air particulate sampler
Air filter
Laboratory weighing scale
Pen or pencil
Paper
Calculator

Instructions

- 1
  Set up the ambient air particulate sampler. It should be placed on a stable surface, 2 to 3 feet away from any walls, furnishings, plants or other items that might obstruct air flow. Most air samplers have a section to input temperature. Some may also require pressure or humidity readings.
- 2
  Put the air filter on the scale and record the weight. Place the filter in the air sampler.
- 3
  Turn on the air sampler. Make sure it is recording the total volume of filtered air. According to the Environmental Protection Agency's National Ambient Air Quality Standards (NAAQS), the air sampler should be run for 24 hours.
- 4
  Turn off the air sampler and remove the air filter. Carefully place the filter on the scale and record the weight.
- 5
  Calculate the concentration of particulate matter. Subtract the weight of the air filter before sampling from the weight of the air filter after sampling. This gives the total weight of the particulate matter. Divide this number by the total volume of air filtered (which was recorded by the air sampler). The result is concentration of particulate matter in micrograms per cubic meter of air.

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