The Carbonaceous Aerosol Speciation System (CASS) from Magee Scientific is a combination of the Aethalometer® Model AE36s /AE36 and the Total Carbon Analyzer TCA-09. It is a versatile instrument for measuring total (TC), elemental (EC) and organic (OC) carbon as well as the black carbon (BC) content of suspended aerosol particles in near-realtime.