Polymerizations are excellent candidates for in-situ reaction monitoring while under precise control using an automatic lab reactor. Many of these reactions are run at high temperatures and/or pressures, some are extremely oxygen sensitive and many involve the use of hazardous reagents, which make them problematic for off-line sampling. By using accurate temperature measurement as an in-situ analysis technique, automated lab reactors provide analytical information about the heat of reaction, the heat transfer properties, the rate of reaction and kinetics � all of which can be used for reaction design and a safe scale-up. Results of case studies will be presented.