MyPart, An Open Source Portable Air Particle Counter
One of the most harmful airborne pollutants with respect to human health is particulate matter. Air particle counters are used to determine the air quality by counting and sizing the number of particles in the air. This information is useful in determining the amount of particles inside a building or in the ambient air. It is also useful in understanding the cleanliness level in a controlled environment.
Airborne particles with a diameter of less than 10 microns pose a large risk, they can travel deeply into the respiratory system, causing a variety of cardiovascular and respiratory diseases. Combustion (e.g. burning wood; automobiles) can generate particles less than 2.5 microns in diameter. Between 2.5 and 10 microns are particles such as dust, pollen, and mold. (More information about particulate matter can be found here.)
MyPart’s design focuses on four goals; accuracy, size and portability, cost, and open source.
In the test chamber, smoke concentration was allowed to decay naturally over about 2 hours. Three prototypes of MyPart gave similar accuracy results to an expensive instrument results ($5000 MetOne HHPC-6).
Additional experiments conducted with calibration particles of known sizes and in outdoor ambient environments, and more information about the tests can be found here.
Size & Portability
The overall size of the inner sensing chamber is 18mmx38mmx45mm. These dimensions include an onboard 400mAh battery. The components related to the sensing are completely separated from the outer casing, which allows various form factors to easily be explored, developed, and shared.
MyPart sensor consumes about 2 mA while sleeping, and about 70mA during sampling.