Laser particle counters are handheld devices which can help you monitor indoor air quality by detecting particles as small as 0.3 microns in size. These include common allergens like pollen, fine dust, pet dander, and mold spores.

Knowing the size of these particles can be helpful when considering the purchase of HVAC air filters, an air purifier, or other appliance to help eliminate them and create healthier indoor air.

How Laser Particle Counters Work:

A laser particle counter uses scattered light technology to detect particles of various sizes suspended in the air within a space. This data is expressed as the concentration of particles in a specified cubic-foot volume of air. Depending on the model of your particle counter, you may see the number of large particles and the number of small particles displayed separately.

The particle sizes monitored can vary from model to model, anywhere from as small as 0.3 microns as a minimum, up to 25 microns as a maximum. Although particle monitors can’t tell you what kinds of particles are being measured, you’ll know the concentration of the different sizes of the suspended particles in the air.

Features to Look for in a Laser Particle Counter:

There is a fairly wide variety of laser particle counters on the market for a similarly wide range of prices. While commercial particle counters are highly accurate and sensitive to very tiny particles, they’re also on the high end of the price range and may be overkill for home use.

Laser particle counters designed for home use have a handful of features that make taking particle counts simple and analyzing them easy.

  • Particle Size Sensitivity: Most residential laser particle counters can detect particles 0.5 microns and larger. But if you have severe allergies, you might need one with increased sensitivity to smaller particles, as small as 0.3 microns.
  • Fast Sampling: Look for a particle counter that provides quick sampling, from just a few minutes to a matter of seconds. With fast results, you’ll be able to take action sooner.
  • Multiple Sampling Modes: This feature gives you more options when it comes to analyzing the air’s particle counts. For example, a continuous mode samples your air non-stop, while an intermittent mode samples your air at set intervals.
  • Data Storage: It can be helpful to understand particle count over time to track trends of seasonal highs and lows. A particle counter that logs and stores data makes tracking and comparing counts simple, enabling you see how an air purifier or other IAQ improvement treatment is working.
  • Size and Weight: Obviously there can be several rooms that need a particle counter. A model that is compact and easily portable will make this process easiest.

Size Chart for Airborne Pollutants:

particle sizes by type

Tracking the particle count can help you determine what might be the most effective treatment for your Indoor Environment, and then track how well the treatment is controlling the target allergens or pollutants on an ongoing basis.

In Summary:

Laser particle counters are simple devices which literally count tiny particles polluting your indoor air. Based on the size and concentration, you can know best how to eliminate them using one of a variety of methods, from furnace filters to HEPA air purifiers.