Abstract: A high temperature light scattering measurement device for characterizing certain physical properties of molecules is described. In one embodiment the device includes a sample scattering chamber having at least one detector positioned about the chamber so as to collect light scattered by the molecules to be characterized located within the sample chamber. The sample scattering chamber, detectors and associated optics are located within an oven to maintain the scattering chamber at an elevated temperature. Light to be scattered by molecules in the sample scattering chamber is provided by a laser located outside the oven. Light from the laser is directed along an optical path through the oven wall where it is then focussed by optical elements on the sample chamber.