The effects of fine particulate matter (PM(sub 2.5)) on human health are well documented. In order to spatially and temporally assess the impact of PM(sub 2.5) on the U.S. population, the U.S. Environmental Protection Agency (U.S. EPA) operates a network of Federal Reference Method (FRM) air quality monitors which measure ambient PM(sub 2.5) concentration in locations that are important due to the need to track compliance with the National Ambient Air Quality Standards (NAAQS) mandated concentration levels in geographic regions of interest and to assess exposures of local populations where the monitors are located. When scientists attempt to correlate ambient concentration levels of PM(sub 2.5) to documented health outcomes, in most cases, they are forced to use the PM(sub 2.5) concentration measurement values from the monitor(s) closest to the study area as a surrogate for measuring ambient PM(sub 2.5) concentration at (or nearer to) the actual location of the study population(s). Due to prohibitive cost, land-use concerns, and EPA's current strategy for locating air quality monitors, it is not practical to place PM(sub 2.5) FRM monitors more closely to improve measurement of ambient PM(sub 2.5) concentration for health studies. The standard FRM monitors used to determine the ambient concentration of PM(sub 2.5) are filter-based, and the schedule for filter collections is either once every three days (1-in-3) or once every six days (1-in-6). The PM(sub 2.5) particles collected on the filters are weighed and the daily concentration of PM(sub 2.5) determined for each monitor/site. A number of technologies/methodologies have been developed for Federal Equivalent Method (FEM) monitors, which measure PM(sub 2.5) particles in a continuous/semi-continuous (non-filter based) manner and provide ambient concentration measurements of PM(sub 2.5) on an hourly basis.