Filter loading corrections for real-time aethalometer measurements of fresh diesel soot. (2007)

TitleFilter loading corrections for real-time aethalometer measurements of fresh diesel soot. (2007)
Publication TypeJournal Article
Year of Publication2007
AuthorsJorge Jimenez, Candis S Claiborn, Timothy Larson, Thomas W Kirchstetter, Lara A Gundel
JournalJournal of Air and Waste Management Association
Volume57
Issue7
Pagination868–873
Abstract

In this study, a correction was developed for the aethalometer to measure real-time black carbon (BC) concentrations in an environment dominated by fresh diesel soot. The relationship between the actual mass-specific absorption coefficient for BC and the BC-dependent attenuation coefficients was determined from experiments conducted in a diesel exposure chamber that provided constant concentrations of fine particulate matter (PM; PM(2.5); PM < 2.5 microm in aerodynamic diameter) from diesel exhaust. The aethalometer reported BC concentrations decreasing with time from 48.1 to 31.5 microg m(-3) when exposed to constant PM(2.5) concentrations of 55 +/- 1 microg m(-3) and b(scat) = 95 +/- 3 Mm(-1) from diesel exhaust. This apparent decrease in reported light-absorbing PM concentration was used to derive a correction K(ATN) for loading of strong light-absorbing particles onto or into the aethalometer filter tape, which was a function of attenuation of light at 880 nm by the embedded particles.