AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
On the Use of the Field Sunset Semi-continuous Analyzer to Measure Equivalent Black Carbon Concentrations
Nadežda Zíková, Petr Vodicka, Wolfgang Ludwig, Regina Hitzenberger, JAROSLAV SCHWARZ, Institute of Chemical Process Fundamentals CAS
Abstract Number: 332 Working Group: Instrumentation and Methods
Abstract This study describes a method how to calculate EBC concentrations obtained from raw laser intensity data measured by a semi-continuous thermo-optical EC/OC analyzer (Sunset Laboratory Inc., USA), compares the calculated EBC concentrations to several EBC-dedicated instruments, and introduce a new correction method for EBC determination.
During two intensive campaigns in Prague, Czech Republic during summer and winter campaign in 2012 and 2013, the derived EBC data were compared to EBC-dedicated filter-based instrumentation: MAAP (5012, Thermo Scientific), aethalometer (AE31, Magee Scientific), and microaethalometer (AE51, AethLab AE51). The EBC concentrations from all instruments were compared to the MAAP EBC concentrations with a good agreement in both the summer and winter campaigns. Several corrections were applied on EBC data as well to show the applicability, advantages, and also disadvantages of deriving EBC concentrations from the EC/OC analyzer, originally not intended to EBC measurements. The derived EBC data were corrected for simple loading, multiple scattering, and wall reflection correction for a quartz tube in the semi-continuous analyzer.
Based on the analyses, we conclude it is necessary to correct the laser signals given by the Sunset semi-continuous analyzer for light reflection on the quartz tube, with new correction introduced. With the new correction, it is possible to use the semi-continuous Sunset analyzer to derive EBC concentrations with a reasonable agreement to aethalometer data with no additional costs or alterations of the instrument, and same possibilities of additional corrections. In the absence of a dedicated instrument, EBC from the semi-continuous Sunset analyzer can be used to get a reasonable indication of EBC concentrations.
This work was performed in the framework of a project by the ÖAD, WTZ CZ 03/12, MEYS MOBILITY grant No. 7AMB12AT021, and the infrastructure project of the MEYS of the Czech Republic ACTRIS-CZ - LM2015037.