Abstract: The system consists of a light source, a monochrometer, one or more etalons or other stable samples, a detector and a computer to store reference spectra, provide a read out indicative of the spectrum, and to change the instrument response. A transfer function is used to recharacterize the instrument's wavelength position and intensity response to match the actual spectrum with the standard spectrum. In one embodiment, the etalon is used in series with the unknown sample. A spectrum of the sample and etalon is created and is extracted from the spectrum of the sample alone to provide the actual spectrum of the instrument response to the etalon alone. The actual spectrum can then be compared to the standard spectrum and the instrument response recharacterized accordingly.

Abstract: A process control method for controlling a polyolefin polymerization process, such as a solution polyethylene process, which includes five steps. The first step is to flow a stream of a solvent into a polyolefin reactor, such as flowing a stream of heptane solvent into the reactor at essentially a constant rate. The second step is to add a principal monomer to the stream of solvent, such as by adding ethylene at a controllable rate to the stream of solvent. The third step is to add a co-monomer to the stream of solvent, such as by adding 1-octene at a controllable rate to the stream of solvent.

Abstract: A method for sorting a plurality of diverse objects into groups, each such object being made predominately from at least polyethylene terephthalate and polystyrene and at least two of polyvinyl chloride, polyethylene and polypropylene, the groups consisting at least of objects of like type of polymer identified to be polyethylene terephthalate and polystyrene and at least two of polyvinyl chloride, polyethylene and polypropylene. The method includes three steps. The first step is to irradiate the objects to be sorted with near-infrared radiation. The second step is to measure the diffuse reflectance of the irradiated objects in the near-infrared region to identify the objects as to the type of polymer used to make them. The third step is to direct the objects to their respective groups according to the measurement and identification of the second step.