40The information in this section applies to the most common samplers in the STN

network. Some networks use alternative special purpose samplers to collect both PM2.5 and

PM2.5 speciation data. The characteristics of the sampler and the analytical procedures used to

produce chemical speciation data should be considered in determining which, if any adjustments

are appropriate to make the data useful for comparison to FRM data.

41The draft PM2.5 modeling guidance recommended a mass reconstruction scheme that

was identical to the IMPROVE technique. We are still recommending use of IMPROVE

assumptions for regional haze modeling (see section 6).

2006). This characterization of PM2.5 mass also reflects “other” primary inorganic PM2.5 and

other minor constituents. Frank (2006) terms this approach “sulfate, adjusted nitrate, derived

water, inferred carbonaceous material balance approach (SANDWICH)”. The resulting

characterization provides a complete mass balance. It does not have any unknown mass which is

sometimes presented as the difference between measured PM2.5 mass and the characterized

chemical components derived from routine speciation measurements. The recommended SMAT

characterizations should yield more accurate assessments of future PM2.5 concentrations as

measured by FRM monitors.

5.1.4 Recommended Treatment of Species Data

As noted above, special treatment of species component mass is recommended in the

SMAT methodology. The goal is to reconstruct the measured species components so that they

add up to the measured FRM mass. This concept can generally be represented by the following


RCFMFRM = [Ammoniated Sulfate Mass] + [Retained Nitrate Mass] + [Retained Carbonaceous

Mass] + [Other Primary PM2.5 ] + [Other Components] [5.1]

In the above characterization, RCFM equals reconstructed


n601 - n602 - n603 - n604 - n605 - n606 - n607 - n608 - n609 - n610 - n611 - n612 - n613 - n614 - n615 - n616 - n617 - n618 - n619 - n620 - n621 - n622 - n623 - n624 - n625 - n626 - n627 - n628 - n629 - n630 - n631 - n632 - n633 - n634 - n635 - n636 - n637 - n638 - n639 - n640 - n641 - n642 - n643 - n644 - n645 - n646 - n647 - n648 - n649 - n650


   Flag of Portugal 


 castellano: DISPER CUSTIC DESCAR RADIA    italiano:     


 français:    português:  






deutsch: DIS CUS  DES  RAD

castellano: DIS CUS DES  RAD   english: DIS CUS DES RAD  


 português: DIS CUS DES RAD   italiano:   DIS CUS  DES RAD


français:  DIS CUS DES RAD