A new unique method, ACOMP, of directly monitoring and measuring polymerization processes in real time was tested with SBR. ACOMP yields continuous data on important characteristics of the reaction and resulting polymers. The polymer properties include conversion, molecular weight, reduced viscosity, and shear thinning viscosity. The system yields continuous average values, such as Mw, rather than the intermittent molecular weight distributions (MWD) provided by GPC. The work detailed in this presentation, conducted in conjunction with Bridgestone Research Americas, outlines results obtained from the application of ACOMP to SBR reactions. ACOMP was used to continuously measure the anionic polymerization of styrene butadiene rubber (SBR) at the 20 L scale. The system successfully demonstrated that it can track conversion, along with weight average molecular weight (Mw), and low and high shear reduced viscosities (RV). After the initial reaction, the effects of the coupling agent were directly monitored by ACOMP. This showed a doubling in Mw over time and increases in RV commensurate with what one expects for random coils in a good solvent. ACOMP proved the capability of directly monitoring and characterizing polymer conversion, Mw, and RV of the polymers produced during a living, anionic solution based SBR polymerization process. This information is directly important with respect to characterizing the macromolecular polymer properties of Mw and RV, and it is also useful in providing insights into production rates and efficiencies, such as improving cycle time and yields while achieving product consistency from batch to batch.