Development of a near infrared spectroscopy analyzer for on-lineprocess analysis

摘要

An on-line near infrared analytical system was developed for on-line process analysis applications. The system includesa near infrared spectroscopy analyzer and accessories (fibers, flow cell, diffuse reflection probes etc.). Its features andconfiguration were described in detail. Good performance was acquired: the wavelength range, resolution and stray lightof spectra are 1000nm-2500nm, less than 5nm and less than 0.1%, respectively; the repeatability and uncertaintytolerances of wavelength are less than 0.02nm and 0.lnm, respectively; the temperature-induced drift of wavelength isless than 0.05nm/°C; the slope and intercept ranges are 0.98-1.00 and -0.02-0.01 for photometric linearity, respectively;spectrophotometric noise is 1.3x10~(-5)(RMS) for high-light flux and 7.0x10-5(low-flux. The aboveperformance parameters of the analyzer meet and exceed the requirement of USP 1119. Furthermore, the analyzer hasbeen successfully applied to the laboratory, petrochemical factory and sugar mill. A Partial Least Squares (PLS)calibration model constructed from laboratory and factory samples was used for these applications. The applicationresult reveals that the analyzer can meet all requirements. All results demonstrate that the analyzer has the merits of fast time response , excellent modeling, high accuracy and low maintenance cost and can deal with complex industrialenvironment.