Evaluation of emerging diesel particulate emissions control technology will require analytical procedures capable of continuous measurement of transient organic and elemental carbon emissions. Procedures based on the flame ionization properties of organic carbon and the opacity or light extinction properties of elemental carbon are described. The instrumentation provided adequate time resolution to observe the transient concentrations associated with typical automobile driving patterns. Accuracy and precision are evaluated by comparing integrated average results to measurements, using classical gravimetric filtration techniques. Emissions from two diesel passenger cars with substantially different chemical compositions are examined. Mass specific extinction coefficients are developed using the Beer-Lambert Law and a simplified linear model which proved adequate for particulate concentrations typical of diluted passenger car exhaust. (Copyright (c) 1988 APCA.)