A Demonstration of Truly Remote In-Line Near-Infrared Process Analysis

A system for truly remote near-infrared (NIR) analysis of multiple process streams is described. The system utilizes a standard laboratory Fourier transform (FT) NIR spectrophotometer, housed remotely from the plant in a safe area. NIR radiation is transmitted between the spectrophotometer and the process stream by a pair of multimode silica optical fibers and an optical multiplexer. The qualitative and quantitative performance of the system, over the 1- to 2-μm region, is demonstrated with total optical fiber lengths of 2 km. The results of an analysis of a set of aliphatic alcohol mixtures, using the process analysis system, are compared with those obtained with a normal laboratory instrument.