Carbonaceous Aerosol Speciation System CASS

• DUALSPOTTM TECHNOLOGY for yielding Black Carbon result independent of the so-called “filter loading effects.”
• CONTINUOUS ANALYSIS OF TOTAL CARBON content using 2 identical flow channels with 2 independent stainless steel combustion chambers.
• SOURCE APPORTIONMENT to discriminate Black Carbon from fossil fuel vs. Black Carbon from biomass burning with built-in analysis by a 2-component model.
• CALIBRATION/VALIDATION against NIST STANDARD reference material to validate the data by a Neutral Density Optical Filter Kit data. This procedure can be performed at the instrument site to maximize up-time and minimizes expenses.
• Using AMBIENT AIR in the combustion chamber as a carrier gas to create CO2 pulse and measures the level of TC in ambient air, therefore NO special GAS and NO special quartz GLASS are required.
• RUGGED and ALL STEEL CONSTRUCTION to fit the requirements of standardized 19” rack type mounting.
• EASY INSTALLATION and MAINTENANCE and VERY LONG AUTONOMOUS OPERATION

The Carbonaceous Aerosol Speciation System CASS provides real-time data for BC, closely related to EC. It automatically combines them with TC data from TCA08  to provide a complete characterization of the carbonaceous component of the aerosol in near-real-time: TC, BC, (or ´EC´), and OC. All carbonaceous aerosol components are characterized by including a simple mathematical relation: TC = BC (EC) + OC.

CASS uses the advanced TC/BC(l) method to study the influence of anthropogenic processes, such as fossil fuel combustion (traffic) or biomass burning (wildfires), on air quality and thus to study the impact of those processes on our daily life, e.g., climate change and public health.

Complete carbonaceous aerosol fingerprint can be obtained from CASS: BCff, BCbb, POAnon-abs, POABrC, SOAnon-abs, and SOABrC. All data obtained from CASS instrument can be afterwards further analyzed by taking into account some specific numerical models (Aethalometer model, Brown Carbon model, EC-BC tracer, BC tracer for BrC, OC-OM model by including MAC values for Black Carbon @ 880 nm and Primary/Secondary Brown Carbon @ 370 nm) to finally obtain the complete CA fingerprint as schematically shown in a chart below.

Refer to this application for more details.

The Carbonaceous Aerosol Speciation System CASS discriminates a Black Carbon fossil fuel from a Black Carbon biomass burning (%BB) in real-time through a sophisticated built-in SW analysis based on a two-component Aethalometer model.

The BC (´EC´) optical analysis is performed at 7 wavelengths from the near-infrared (950 nm) to the near-ultraviolet (370 nm), yielding optical absorption characteristics of collected aerosols on a Teflon-coated glass fiber filter tape. Tape advances automatically when the user-selectable loading threshold is reached, typically once every few hours, depending on aerosol concentration and airflow rate.

The Carbonaceous Aerosol Speciation System CASS is constructed in a rugged and compact design to fit AE33 and TCA08 into a 19” rack type CASS housing package suitable for field-work laboratory routine Air Quality monitoring applications with limited space. CASS can operate for a longer period of time (from weeks to months) without the operator´s attention; only a roll of filter tape on AE33 and quartz fiber filter or denuder on TCA08 must be replaced from time to time.