Optical Fiber Instrumentation for Online Absorption and Reflection Spectroscopy

摘要

The proposed instrumentation is compact, portable, and it enables easy interchangeably among various kinds of probes. The use of LEDs and microspectrometer enabled creation of low-cost instrumentation that operates over the entire visible spectral range. The optoelectronic modules can be advantageously multiplexed to address optical fiber sensor arrays made of fiber optic bundles, each of whose fibers are sensitive to a different analytical parameter. The spectrophotometers were validated through direct spectroscopy and the interrogation of optrode-based optical fiber sensors. The following absorption and reflection spectroscopy measurements were performed: 1. Absorption measurements: colorimetry of liquid samples, including gasoline blends and waste water discharges containing chromium. 2. Reflection spectroscopy measurements: surface colorimetry. Designed for the color analysis of liquids and surfaces in industrial process control, water analysis, and food processing control, the proposed spectrophotometers can be used in other colorimetric applications by operators with little or no technical background. The presence of colorimetric passive samplers acting as dosimeters for gaseous pollutants and acids enables the proposed instrumentation to act as an in-situ spectrophotometric laboratory, i.e. a totally, autonomous nonstop monitor of passive samplers in environmental and industrial applications.