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.

Abstract: A molecular characterization detector includes a scattering cell containing a sample for molecular characterization, a light source for directing a light beam through the cell so that the light beam is scattered by the sample, optical elements for selecting from the scattered light a measurement beam comprising light that is scattered by the sample from a predetermined portion of the cell in a predetermined range of angles relative to the optical axis, and a detector for detecting the measurement beam and providing an output electrical signal representative of the measurement beam. The detector typically selects light scattered from a central portion of the scattering cell at angles in the range of 14.degree. to 16.degree.. A single spherical lens is preferably utilized. As a result, interference from stray scattered light is minimized. A beam dump attenuates the light beam after it passes through the scattering cell. Additional detectors detect light scattered at 90.degree. to the light beam.