We recently received two used Airmetrics MiniVol PM samplers from Global Community Monitor. The MiniVol is a low-volume, battery powered, filter-based sampler. In filter-based samplers, size-sorted particles are captured on a filter that is then weighed ('gravimetric analysis') to determine the concentration of particulate matter in the air pumped through the monitor (see more in the wiki). The MiniVol is designed for 24-hour samples that correspond with Federal Reference Method (FRM) monitors, but due to their lower air volume are not considered FRM-grade.
We're hoping to pilot how to calibrate and deploy these monitors with community groups, and will follow this note with more information on cleaning, calibrating, and using the MiniVol.
The MiniVol comes with chargers, outdoor mounts, and consumables neatly mounted inside its shipment-ready box:
Clockwise from top: Minivol, PM2.5 impactor, PM10 impactor, manual, battery pack.
How the MiniVol Works
The minivol has two different impactors, one for PM2.5, and one for PM10 (pictured up top, on the right). Impactors work to inertially sort particles:
The MiniVol impactor:
Because the MiniVol uses filters and an impactor, it must have the grease on its impactor plate replaced and cleaned every five sample periods, and it requires a new filter for every sample.
47mm Quartz, Fiber, or Teflon Filters are pre-weighed at a lab and packaged in cases with a unique ID number. Airmetrics sells filters and analysis services. Different filters are useful for different sorts of monitoring. Teflon filters are used for inorganic contaminant analysis, Quartz for organic contaminant analyis, and Fiber filters for gravimetric analysis (weighing).