Gel Permeation Chromatography (GPC/SEC) equipment category specialized for molecular weight distribution measurement of polymer materials in manufacturing. Performs precise measurement of molecular weight, molecular weight distribution, and polydispersity for quality control, R&D, and product inspection in manufacturing processes of resins, plastics, rubber, adhesives, and coatings. Includes main unit, dedicated columns, differential refractive index detector, viscosity detector, light scattering detector, solvent delivery pump, autosampler, and molecular weight standards. Essential specialized analytical equipment for polymerization reaction control and product quality evaluation in chemical, petrochemical, and resin manufacturers, with separation principles and applications clearly different from general liquid chromatography.