Challenges with Integrated Measurements of OC and BC (or EC) J. R. Brook, X. Fan, G. Lu EMEP Workshop on Particulate Matter Measurement & Modeling New Orleans, LA April 2004

Conclusions The carbonaceous fraction of PM needs to be measured, but there are challenges associated with: actually defining sub-fractions of the carbon the sampling methodology the laboratory analysis assuring quality in routine programs These challenges make it even more difficult for the modeling community to develop approaches for predicting carbonaceous PM and for evaluating model estimates using available data. In addition to improving time-integrated measurement approaches for OC and EC (or BC), real-time or time-resolved techniques need to be further explored as they may help reduce sampling and analytical problems while also providing better insight into the true atmospheric behavior of PM.

Improving the National Monitoring of OC Figure 2. Schematic of experimental setup Ambient air or Aerosol generator ACF or denuder Impactor D50=2.5µm Pump APS CPC SMPS Aerosol flow GRIMM Particle Counter by-pass flow 5.0 lpm 1.5 lpm

Particle Transmission Through Foam Penetration curves measured for the 1-layer and 2-layer 80ppi ACF; 1- layer and 2-layer 60ppi ACF, at 16.1 cm/s face velocity. All ACF are ¼ inch in thickness, and 47mm in diameter. Penetration curves measured for the 1-layer and 2-layer 80ppi ACF; 1- layer and 2-layer 60ppi ACF, at, at 9.2 cm/s face velocity. All ACF are ¼ inch in thickness, and 47mm in diameter. Penetration curves measured for the 1-layer 80ppi ACF, 1-layer 60ppi ACF, and 2-layer 60ppi foam at a 16.1 cm/s face velocity. All ACF are ¼ inch in thickness, and 47mm in diameter. The particles were from the aerosol generator.