Black carbon measurements using an integrating sphere

An integrating sphere was used to determine the black carbon (BC) content of aerosol filter samples dissolved in chloroform (method originally described by Heintzenberg [1982]). The specific absorption coefficient B-a (equal to absorption per mass) of the samples was also measured using the sphere as an integrating detector for transmitted light. Comparing the B-a of ambient samples taken in Vienna, Austria, to the BC concentrations measured on the dissolved filters, a value of approximately 6 m(2)/g was found to bea a reasonable value for the B-a of the black carbon found at the site. The size dependence of B-a of a nebulized suspension of soot was measured using a rotating impactor, and a reasonable agreement between measured and calculated values was found.